Treatment of Patients with Late-Stage Colorectal Cancer

Publication Date: March 9, 2020
Last Updated: November 8, 2022

Treatment

Recommendations on Symptom Management 

1.1 Patients with advanced-stage colorectal cancer

Clinicians should provide symptom control and establish a management plan with multi-disciplinary approach (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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1.2 Patients with clinically unstable disease due to bowel obstruction or uncontrolled bleeding or uncontrolled pain

Surgical evaluation (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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1.3 Patients with clinically unstable disease due to bowel obstruction or uncontrolled bleeding or uncontrolled pain

If resectable, and urgent surgery required due to obstruction or bleeding: surgery of primary tumor (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal). (S)
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1.4 Patients with clinically unstable disease due to bowel obstruction or uncontrolled bleeding or uncontrolled pain

If unresectable, unable to do biopsy due to clinical scenario, go to ASCO Palliative Care Guidelines (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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1.5 Patients with clinically stable disease with ongoing bleeding from primary site

Transfusion + surgery of primary tumor (ASCO Resource Levels: Basic, Limited) (S)
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Transfusion + multi-disciplinary specialized evaluation (ASCO Resource Levels: Enhanced, Maximal) (S)
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Recommendations on Diagnosis

Pathology

1.6 Patients with advanced-stage colorectal cancer
Tissue handling of pathologic specimen is critical to ensure accurate diagnosis (see Pathology Guidelines - J Clin Oncol 35:1453–1486, 2017) (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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Diagnosis based on primary tumor

1.7 Surgery required to stabilize patient due to obstruction or bleeding
Surgery and surgical specimen to pathology (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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1.8 Patients with clinically stable disease, palpable mass
Biopsy palpable mass (e.g., rectal mass, perianal mass) (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (M)
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1.9 Patients with clinically stable disease, no palpable mass
Flexible sigmoidoscopy (ASCO Resource Levels: Limited) (S)
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Flexible sigmoidoscopy or colonoscopy (ASCO Resource Levels: Enhanced, Maximal) (S)
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1.10 No primary tissue available
Proceed to recommendations on diagnosis based on metastatic disease (Recommendations 1.11 – 1.13) (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) ()
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Diagnosis based on metastatic disease

1.11 Clinically palpable metastatic site
Biopsy palpable mass (e.g., skin nodule, lymph node) (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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1.12 Metastatic disease on staging US or Chest X Ray or CT scan or MRI
Biopsy of metastatic sites under US or fluoroscopy or CT guidance (ASCO Resource Levels: Enhanced, Maximal) (S)
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1.13 Patients with mCRC for whom MDT considers liver or lung surgery
Surgical specimen from metastases resection (e.g., liver, lung) (ASCO Resource Levels: Maximal) (S)
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Molecular testing

1.14 Diagnosis of mCRC based on primary tumor or on metastatic disease
Molecular testing for MSI/MMR, KRAS, NRAS, BRAF should be done based on existing guidelines (ASCO Resource Levels: Maximal) (S)
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Recommendations on Staging

Population: Patients diagnosed with mCRC

1.15
Digital rectal exam (ASCO Resource Levels: Basic, Limited) (S)
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Digital rectal exam (ASCO Resource Levels: Enhanced, Maximal) (W)
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1.16
Chest X-Ray and abdominal ultrasound (US) (ASCO Resource Levels: Basic) (M)
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1.17
Contrast enhanced CT scan chest, abdomen, pelvis (ASCO Resource Levels: Limited, Enhanced, Maximal) (S)
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1.18
PET/CT in selected cases (such as for when MDT is discussing the possibility of a patient receiving resection of metastases) (ASCO Resource Levels: Maximal) (M)
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Population: Liver-only metastatic disease based on imaging staging studies

1.19
Liver MRI or contrast-enhanced liver USa (if MDT available) (ASCO Resource Levels: Limited) (W)
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Liver MRI or contrast-enhanced liver USa (ASCO Resource Levels: Enhanced, Maximal) (M)
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Population: Rectal primary

1.20
MRI pelvis rectal cancer protocol (ASCO Resource Levels: Enhanced, Maximal) (S)
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1.21
Rectal endoscopic ultrasound (ASCO Resource Levels: Enhanced, Maximal) (W)
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First-Line Treatment

2.1 RAS unknown

Palliative care (ASCO Resource Levels: Basic) (S)
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Single agent fluoropyrimidine if available, if not, referral to other facility (ASCO Resource Levels: Limited) (S)
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Doublet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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Doublet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.2 RAS WT and right-sided primary tumor

Doublet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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Doublet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.3 RAS WT and left-sided primary tumor

Doublet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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Doublet chemotherapy ± anti-EGFR (ASCO Resource Levels: Maximal) (M)
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OR doublet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.4 RAS WT ± BRAF MUT, patients with good PS and without major comorbidities, and /or when tumor shrinkage is the goal

Triplet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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Triplet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.5 RAS WT and preexisting neuropathy, elderly, comorbidities, or not candidates for aggressive chemotherapy

Single agent fluoropyrimidine (ASCO Resource Levels: Limited, Enhanced) (S)
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Single agent fluoropyrimidine ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.6 RAS WT and preexisting neuropathy, elderly, comorbidities, or not candidates for chemotherapy

Anti-EGFR monotherapy (ASCO Resource Levels: Maximal) (M)
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2.7 RAS WT and very poor performance status (PS 3–4) or comorbidities

Supportive care only (ASCO Resource Levels: Basic, Limited, Enhanced, Maximal) (S)
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2.8 Any RAS status and dMMR or MSI-H and patients not candidates for intensive chemotherapy

Immune checkpoint inhibitorsa (ASCO Resource Levels: Maximal) (M)
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2.10 RAS MUT

Doublet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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Doublet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.11 RAS MUT and patients with good PS and without major comorbidities, or when tumor shrinkage is the goal

May offer triplet chemotherapy (ASCO Resource Levels: Enhanced) (S)
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May offer triplet chemotherapy ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.12 RAS MUT and preexisting neuropathy, elderly, comorbidities, or not candidates for aggressive chemotherapy

Single agent fluoropyrimidine (ASCO Resource Levels: Limited, Enhanced) (S)
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Single agent fluoropyrimidine ± anti-VEGF (bevacizumab) (ASCO Resource Levels: Maximal) (M)
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2.13b Patients treated with oxaliplatin-based doublet or triplet chemotherapy ± anti-VEGF therapy

Discontinue oxaliplatin after a period of induction if stable disease or response; maintenance single agent fluoropyrimidine ± anti-VEGF therapy; if progression, then reintroduce the first-line therapy or a second-line therapy (ASCO Resource Levels: Maximal) (M)
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2.14b Metachronous metastases, prior oxaliplatin-based chemotherapy for early-stage disease (resectable) ≤12 (aka within) months of mCRC diagnosis

Doublet irinotecan-based chemotherapy (ASCO Resource Levels: Enhanced, Maximal) (S)
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Prior oxaliplatin-based chemotherapy for early-stage disease (resectable) ≥12 months from diagnosis of mCRC

Follow Recommendations in Table 5 ()
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a
Qualifying Statement for First-Line immunotherapy: At the time of this writing, the US Food and Drug Administration (FDA) had not approved the use of immune checkpoint inhibitors (e,g, single agent pembrolizumab or nivolumab or the combination of nivolumab plus ipilimumab) in first-line treatment of patients with mCRC.
b See full text guideline.

Recommendations on Second-Line Systemic Colorectal Metastatic Treatment

Note: This table pertains to Enhanced and Maximal settings, with presumption of lack of chemotherapy in other settings.

3.1 Received oxaliplatin in first line

Irinotecan or irinotecan-doublet (with fluoropyrimidine) (ASCO Resource Levels: Enhanced, Maximal) (S)
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3.2 Received irinotecan in first line

Oxaliplatin-based doublet chemotherapy (with fluoropyrimidine)(ASCO Resource Levels: Enhanced, Maximal) (S)
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3.3 No bevacizumab in first line

Patients may receive alternate chemotherapy ± bevacizumab (ASCO Resource Levels: Maximal) (M)
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3.4 Received bevacizumab in first line

Patients may receive an alternate chemotherapy regimen ± bevacizumab (ASCO Resource Levels: Maximal) (W)
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OR irinotecan-based chemotherapy ± ziv-aflibercept (when treated in first-line with oxaliplatin) (ASCO Resource Levels: Maximal) (W)
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OR irinotecan-based chemotherapy ± ramucirumab (when treated in first-line with oxaliplatin) (ASCO Resource Levels: Maximal) (W)
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OR anti-EGFR therapy + irinotecan-based chemotherapy if RAS wild-type (ASCO Resource Levels: Maximal) (M)
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Anti-EGFR therapy alone (if not candidate for irinotecan) (ASCO Resource Levels: Maximal) (W)
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3.5 RAS WT, received anti-EGFR in first line

Alternative chemotherapy (ASCO Resource Levels: Enhanced) (M)
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Alternative chemotherapy ± anti-VEGF therapy (ASCO Resource Levels: Maximal) (M)
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3.6 BRAF V600E MUT

(see full text guideline: Second-Line Systemic Treatment, Enhanced and Maximal Resource Settings) (ASCO Resource Levels: Maximal) ()
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3.7 dMMR or MSI-high

Immune checkpoint inhibitors (if not previously given) (ASCO Resource Levels: Maximal) (M)
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Recommendations on Third-Line and Fourth-Line Systemic Colorectal Metastatic Treatment

Note: This table pertains to only Maximal settings, with presumption of lack of these agents in in the other settings

4.1 RAS wild type, and no prior anti-EGFR therapy

Anti-EGFR ± irinotecan-based chemotherapya (ASCO Resource Levels: Maximal) (M)
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4.2 any RAS/BRAF

Regorafenibb (if available) OR trifluridine + tipiracilc (if available) (ASCO Resource Levels: Maximal) (W)
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4.3 dMMR/MSI-H

Immune checkpoint inhibitors (if not previously given) (ASCO Resource Levels: Maximal) (M)
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a The combination of cetuximab with irinotecan is more active than cetuximab alone in irinotecan-refractory patients
b Regorafenib is recommended in patients previously treated with fluoropyrimidines, oxaliplatin, irinotecan, bevacizumab and anti-EGFR therapy (if RAS WT)
c Trifluridine/tipiracil is recommended in patients previously treated with fluoropyrimidines, oxaliplatin, irinotecan, bevacizumab and anti-EGFR therapy (if RAS WT)

Recommendations on Liver-Directed Therapies in Patients with Metastatic Colorectal Cancer

Note: This table pertains to only Maximal settings

5.1 Patients with liver metastases

Upfront surgery of metastases (ASCO Resource Levels: Maximal) (S)
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5.2 Highly selected patients with liver metastases

Combination surgery and ablation (ASCO Resource Levels: Maximal) (M)
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5.3 Patients with liver metastases

Ablative therapies: radiofrequency, thermal, cryoablation, alcohol ablation
Radiation therapies: external beam radiation, SBRT
(ASCO Resource Levels: Maximal) (W)
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In Maximal Settings, when patients are deemed to have unresectable liver metastases, depending on institutional expertise and after careful review by MDT, patients may receive/discuss the options of 5.4 – 5.6.

5.4 Patients with liver metastases*

Hepatic arterial infusion (HAI) of chemotherapy in combination with systemic chemotherapy.
Qualifying statement: HAI therapy has limited availability in the USA and is used only in institutions with high level of expertise for this procedure and for select patients.
(ASCO Resource Levels: Maximal) (W)
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5.5 Patients with liver metastases*

Transarterial chemoembolization (TACE) (ASCO Resource Levels: Maximal) (W)
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5.6 Patients with liver metastases*

Selective internal radiation therapy (SIRT) in combination with systemic chemotherapy may be discussed to prolong time to liver disease progression in the second-line setting or beyond. (ASCO Resource Levels: Maximal) (M)
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* NOTE: Recommendations should be implemented in centers of expertise in the specific technique after multidisciplinary review, or in the context of a clinical trial.

Summary Treatment Options for Late-Stage Colorectal Cancer

Surgery Approaches for the Primary Tumor

6.1 mCRC
If high risk of obstruction, significant bleeding, perforation or tumor related symptoms: resection of primary tumor (ASCO Resource Levels: Basic, Limited) (S)
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OR if obstruction from primary tumor or from peritoneal metastases: diverting ostomy (ASCO Resource Levels: Basic, Limited) (S)
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If high risk of obstruction, significant bleeding, perforation or tumor related symptoms: resection of primary tumor (ASCO Resource Levels: Enhanced, Maximal) (S)
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OR if obstruction from primary tumor or from peritoneal metastases: diverting ostomy (ASCO Resource Levels: Enhanced, Maximal) (S)
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OR if obstruction from primary tumor: stenting (ASCO Resource Levels: Enhanced, Maximal) (M)
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Radiation Therapy of Primary Tumor

6.2 mRectal
If symptomatic primary rectal tumor, radiation therapy (± chemotherapy) should be discussed (ASCO Resource Levels: Enhanced, Maximal) (M)
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Systemic Treatment

6.3 mCRC
Fluoropyrimidines (ASCO Resource Levels: Limited) (S)
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Fluoropyrimidines plus oxaliplatin (ASCO Resource Levels: Enhanced) (S)
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OR irinotecan (ASCO Resource Levels: Enhanced) (S)
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Fluoropyrimidines plus oxaliplatin (ASCO Resource Levels: Maximal) (S)
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OR irinotecan (S) + anti-VEGF (ASCO Resource Levels: Maximal) (M)
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OR anti-EGFR (ASCO Resource Levels: Maximal) (M)
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OR immune check-point inhibitors (ASCO Resource Levels: Maximal) (M)
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OR BRAF inhibitors (ASCO Resource Levels: Maximal) (W)
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Surgery for Metastatic Disease Post-Systemic Treatment

6.4 mCRC who have received systemic treatment
Synchronized or staged resection ± ablation of colon/rectal primary tumors and metastatic lesions if they become resectable/amenable to ablation after NACT (ASCO Resource Levels: Maximal) (S)
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Systemic Treatment After Primary Tumor and Metastases Surgery/Ablation

6.5 mCRC who have received surgery/ablation
Fluoropyrimidines (ASCO Resource Levels: Limited) (S)
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Fluoropyrimidines plus oxaliplatin (ASCO Resource Levels: Enhanced) (S)
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OR irinotecan (ASCO Resource Levels: Enhanced) (S)
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Fluoropyrimidines plus oxaliplatin (ASCO Resource Levels: Maximal) (S)
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Recommendations on Surveillance/Follow-Up

7.1 Patients with metastatic disease on active treatment or who are off chemotherapy but in surveillance

ASCO Resource Levels: Basic
Clinical evaluation (medical history and physical exam), every 1–2 months (S)
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AND blood work (complete blood count, metabolic panel including liver and renal tests), chest X-ray, and abdominal ultrasound every 3–6 months (S)
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ASCO Resource Levels: Limited
Clinical evaluation (medical history and physical exam), every 1–2 months (S)
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AND blood work (complete blood count, metabolic panel including liver and renal tests), and CT scan chest/ abdomen/ pelvis every 3–6 months (S)
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ASCO Resource Levels: Enhanced/Maximal
Clinical evaluation (medical history and physical exam) and blood work (complete blood count, metabolic panel including liver and renal tests, CEA) every month (M)
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AND CT scans chest/ abdomen/ pelvis every 2–3 months (M)
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7.2 Patients with metastatic disease post curative-intent therapies

ASCO Resource Levels: Basic
Clinical evaluation (medical history and physical exam) (S)
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AND chest X-Ray and abdominal ultrasound every 6 months for a minimum of 3 years (S)
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ASCO Resource Levels: Limited
Clinical evaluation (medical history and physical exam), CEA, every 6 months for 5 years (S)
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AND CT scan chest/ abdomen/ pelvis every 6 months for 2 years, then yearly for 3 years (S)
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ASCO Resource Levels: Enhanced, Maximal
Clinical evaluation (medical history and physical exam), CEA every 3–6 months for 2 years, then every 6 months for 5 years (M)
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AND CT scans chest/ abdomen/ pelvis every 3–6 months for 2 years, then every 6 months for a total of 5 years (M)
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Recommendation Grading

Overview

Title

Treatment of Patients with Late-Stage Colorectal Cancer

Authoring Organization

American Society of Clinical Oncology

Publication Month/Year

March 9, 2020

Last Updated Month/Year

November 11, 2024

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Document Objectives

To provide expert guidance to clinicians and policymakers in resource-constrained settings on the management of patients with late-stage colorectal cancer

Target Patient Population

Patients with late-stage colon cancer and patients with late-stage rectal cancer.

Target Provider Population

Medical oncologists, radiation oncologists, surgeons, surgical oncologists, and gastroenterologists

PICO Questions

  1. For each of the resource settings, what is the optimal treatment of patients with late-stage colorectal cancer from initial diagnosis to follow-up?

  2. What are the optimal methods of initial symptom management, diagnosis, and staging for patients with late-stage colorectal cancer?

  3. What are the optimal systemic treatments for patients with late-stage colorectal cancer in first line?

  4. What are the optimal treatments for patients with late-stage colorectal cancer who have received one prior line of therapy?

  5. What are the optimal treatments for patients with late-stage colorectal cancer who have received two prior lines of therapy?

  6. What are selected liver-directed therapy options for patients with late-stage colorectal cancer and liver metastases?

  7. What is a summary of the optimal treatments for patients with late-stage colorectal cancer?

  8. What are the optimal on-treatment surveillance and follow-up strategies for patients treated for mCRC?

Inclusion Criteria

Male, Female, Adult, Older adult

Health Care Settings

Ambulatory, Hospital, Outpatient, Radiology services

Intended Users

Nurse, nurse practitioner, physician, physician assistant

Scope

Treatment, Management

Keywords

cancer resource stratification, colorectal cancer, resource stratification, late-stage cancer, rectal cancer

Source Citation

DOI: 10.1200/JGO.19.00367 JCO Global Oncology no. 6 (2020) 414-438. Published online March 9, 2020.

Methodology

Number of Source Documents
77
Literature Search Start Date
January 1, 2012
Literature Search End Date
July 31, 2018
Description of External Review Process
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ASCO Guidelines are available for open comment for a 2 to 3‐week period. Guideline recommendations available for open comment are posted on asco.org/open‐comment‐guidelines. Prospective reviewers must contact ASCO to request to review the draft guideline recommendations and are required to sign a non‐disclosure and confidentiality agreement before receiving the draft guideline recommendations. Reviewers must identify themselves by name and affiliation; anonymous comments will not be accepted. Guidelines staff review and summarize comments and bring relevant comments to the Expert Panel Co‐ chairs, and to the entire panel if necessary. Any changes made from the open comment process will be reviewed by the entire panel prior to CPGC approval. Comments are advisory only and ASCO is not bound to make any changes based on feedback from open comment. ASCO does not respond to reviewers or post responses to comments; however, major edits to the draft will be reflected in the open comment discussion.
Specialties Involved
Gastroenterology, Oncology, Medical Oncology, Surgical Oncology, Radiation Oncology, Oncology, Oncology, Oncology
Description of Systematic Review
The Protocol specifies the purpose of the guideline product, target patient population, clinical outcomes of interest, key features of the systematic literature review, and a proposed timeline for completion. ASCO staff, the Expert Panel Co‐Chairs, and possibly other panel members selected by the Co‐Chairs (the Expert Panel Steering Committee), will typically draft the protocol for full panel review. A standard protocol worksheet is used for consistency. Once the Co‐Chairs have approved a first draft of the Protocol, the Protocol will be shared with the full Expert Panel. At the discretion of the Guidelines Director, the CPGC leadership and/or the CPGC Methodology Subcommittee may review the Protocol to make suggestions for revision intended to clarify aspects of the plan for developing the guideline. These suggestions are sent to the Expert Panel Co‐Chairs. Work on the systematic literature review can proceed upon the sign‐off of the Protocol by the Expert Panel.
List of Questions
Full-text
Description of Study Criteria
Methodology Supplement
Description of Search Strategy
Upon approval of the Protocol, a systematic review of the medical literature is conducted. ASCO staff use the information entered into the Protocol, including the clinical questions, inclusion/exclusion criteria for qualified studies, search terms/phrases, and range of study dates, to perform the systematic review. Literature searches of selected databases, including The Cochrane Library and Medline (via PubMed) are performed. Working with the Expert Panel, ASCO staff complete screening of the abstracts and full text articles to determine eligibility for inclusion in the systematic review of the evidence. Unpublished data from meeting abstracts are not generally used as part of normal ASCO guideline development (“Meeting Data”). However, abstract data from reputable scientific meetings and congresses may be included on a case‐by‐case basis after review by the CPGC leadership. Expert Panels should present a rationale to support integration of abstract data into a guideline. The CPGC leadership will consider the following inclusion criteria for the unpublished scientific meeting data: 1) whether the data were independently peer reviewed in connection with a reputable scientific meeting or congress; 2) the potential clinical impact of the unpublished data; 3) the methodological quality and validity of the associated study; 3) the potential harms of not including the data; and 4) the availability of other published data to inform the guideline recommendations.
Description of Study Selection
Literature search results were reviewed and deemed appropriate for full text review by two ASCO staff reviewers in consultation with the Expert Panel Co-Chairs. Data were extracted by two staff reviewers and subsequently checked for accuracy through an audit of the data by another ASCO staff member. Disagreements were resolved through discussion and consultation with the Co-Chairs if necessary. Evidence tables are provided in the manuscript and/or in Data Supplement.
Description of Evidence Analysis Methods
ASCO guideline recommendations are crafted, in part, using the GuideLines Into DEcision Support (GLIDES) methodology. ASCO adopted a five‐step approach to carry out quality appraisal, strength of evidence ratings and strength of recommendations ratings. The ASCO approach was primarily adapted from those developed by the AHRQ,, USPSTF, and GRADE, however with the validation of the GRADE methodology, the sole use of GRADE is being evaluated by the Clinical Practice Guidelines Committee.
Description of Evidence Grading
High: High confidence that the available evidence reflects the true magnitude and direction of the net effect (i.e., balance of benefits v harms) and that further research is very unlikely to change either the magnitude or direction of this net effect. Intermediate: Moderate confidence that the available evidence reflects the true magnitude and direction of the net effect. Further research is unlikely to alter the direction of the net effect; however, it might alter the magnitude of the net effect. Low: Low confidence that the available evidence reflects the true magnitude and direction of the net effect. Further research may change either the magnitude and/or direction this net effect. Insufficient: Evidence is insufficient to discern the true magnitude and direction of the net effect. Further research may better inform the topic. The use of the consensus opinion of experts is reasonable to inform outcomes related to the topic.
Description of Recommendation Grading
ASCO uses a formal consensus methodology based on the modified Delphi technique in clinically important areas where there is limited evidence or a lack of high‐quality evidence to inform clinical guidance recommendations. Evidence Based: There was sufficient evidence from published studies to inform a recommendation to guide clinical practice. Formal Consensus: The available evidence was deemed insufficient to inform a recommendation to guide clinical practice. Therefore, the Expert Panel used a formal consensus process to reach this recommendation, which is considered the best current guidance for practice. The Panel may choose to provide a rating for the strength of the recommendation (i.e., "strong," "moderate," or "weak"). The results of the formal consensus process are summarized in the guideline and reported in the Data Supplement (see the Supporting Documents" field). Informal Consensus: The available evidence was deemed insufficient to inform a recommendation to guide clinical practice. The recommendation is considered the best current guidance for practice, based on informal consensus of the Expert Panel. The Panel agreed that a formal consensus process was not necessary for reasons described in the literature review and discussion. The Panel may choose to provide a rating for the strength of the recommendation (i.e., "strong," "moderate," or "weak"). No recommendation: There is insufficient evidence, confidence, or agreement to provide a recommendation to guide clinical practice at this time. The Panel deemed the available evidence as insufficient and concluded it was unlikely that a formal consensus process would achieve the level of agreement needed for a recommendation.
Description of Funding Source
ASCO provides funding for Guideline Development.
Company/Author Disclosures
ASCO Conflict of Interest Policy complies with the CMSS Code for Interactions with Companies. ASCO requires disclosure by individuals involved in drafting, reviewing, and approving guideline recommendations.
Percentage of Authors Reporting COI
100