Key Points
- Historically, some of the highest incidence rates for colorectal cancers have been in “more developed” regions. However, approximately 45% of these occur in “less developed” regions, representing 9-10% of cancers in those populations.
- Since different regions of the world, both among and within countries, differ with respect to resource access, ASCO has established a process for stratifying guidelines according to resource availability (basic, limited, enhanced and maximal – See Table 1). This framework emphasizes that variations occur not only between but also within countries—for example, between rural and urban areas.
Treatment
Table 1. Framework of Resource Stratification
| Setting | |
|---|---|
| Basic | Core resources or fundamental services that are absolutely necessary for any public health/primary health care system to function; basic-level services typically are applied in a single clinical interaction. |
| Limited | Second-tier resources or services that are intended to produce major improvements in outcome such as incidence and cost-effectiveness and are attainable with limited financial means and modest infrastructure; limited-level services may involve single or multiple interactions. Universal public health interventions feasible for greater percentage of population than primary target group. |
| Enhanced | Third-tier resources or services that are optional but important; enhanced-level resources should produce further improvements in outcome and increase the number and quality of options and individual choice. (Perhaps ability to track patients and links to registries) |
| Maximal | May use high-resource settings’ guidelines. High-level/state-of-the art resources or services that may be used/available in some high-resource countries and/or may be recommended by high-resource setting guidelines that do not adapt to resource constraints but that nonetheless should be considered a lower priority than those resources or services listed in the other categories on the basis of extreme cost and/or impracticality for broad use in a resource-limited environment. |
Table 2. Non-metastatic, non-obstructing colon cancer
Colon Cancer Stage I: T1-2N0M0, Colon Cancer Stage IIA: T3N0 (no high-risk features), Colon Cancer Stage IIA: T3N0 (with high risk features)
| Population | Intervention | Setting |
|---|---|---|
| Patients with non-obstructing, resectable, localized colon cancer | General surgeons should perform open resection following standard oncologic principles. (Strong Recommendation; H) | Basic and Limited |
| Patients with non-obstructing, resectable, localized colon cancer | If suitable, surgical oncologists and/or colorectal surgeons with adequate training in laparoscopic or minimally invasive techniques should perform laparoscopic or minimally invasive resection following standard oncologic principles and, if Maximal, using the most appropriate techniques and instruments. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with non-obstructing, resectable, localized colon cancer | If laparoscopy is contraindicated, surgical oncologists and/or colorectal surgeons should use an open surgical approach. (Strong Recommendation; H) | Enhanced and Maximal |
Table 3. Colon Cancer Stages IIB-IIC: T4N0 (Non-obstructing)
| Population | Intervention | Setting |
|---|---|---|
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer | General surgeons should perform an open en bloc resection (including adjacent invaded organ) following standard oncologic principles. (Strong Recommendation; H) | Basic |
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer with contraindications and/or en bloc resection not possible | If contraindications and/or en bloc resection not possible, efforts should be made to transfer a patient to a higher-level facility. (Strong Recommendation; IC-H) | Basic and Limited |
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer with emergent symptoms | In an emergency, surgery performed by general surgeons should be limited to life-saving procedures (ie. segmental resection of bleeding or perforated tumors). (Strong Recommendation; IC-H) | Basic |
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer | General surgeons should perform an open en bloc resection following standard oncologic principles. (Strong Recommendation; H) | Limited |
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer | Colorectal surgeons and/or surgical oncologists should perform a laparoscopic en bloc resection following standard oncologic principles. (Strong Recommendation; H) | Enhanced |
| Patients with non-obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer | If a laparoscopic en bloc resection is not possible, surgical oncologists and/or colorectal surgeons should perform an open approach. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with non-obstructing, resectable, locally advanced (ie., with invasion of adjacent structures) colon cancer | If there are no contraindications, surgical oncologists and/or colorectal surgeons should perform an en bloc resection following standard oncologic principles using the most advanced techniques. (Strong Recommendation; H) | Maximal |
Table 4. Colon Cancer Stages IIB-IIC: T3N0 Obstructing or T4N0 (Obstructing)
| Population | Intervention | Setting |
|---|---|---|
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) resectable colon cancer | General surgeons should perform emergency resection and/or diversion (if resection is not possible) if feasible following standard oncologic principles. (Strong Recommendation; H) | Basic |
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) resectable colon cancer | General surgeons should perform emergency surgical resection and/or diversion following standard oncologic principles. (Strong Recommendation; H) | Limited |
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) resectable colon cancer | Surgical oncologists and/or colorectal surgeons should perform emergency surgical resection and/or diversion following standard oncologic principles. (Strong Recommendation; H) | Enhanced |
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) resectable colon cancer | For left-sided obstructing colon cancers, surgical oncologists and/or colorectal surgeons with specialist skills/training may place a colonic stent. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) resectable colon cancer | Surgical oncologists and/or colorectal surgeons should perform emergency surgical resection and/or diversion following standard oncologic principles using the most advanced techniques. (Strong Recommendation; H) | Maximal |
Table 5. High-Risk Obstructing Colon Cancer and Colon Cancer Diagnoses Eligible for Adjuvant Treatment
| Population | Intervention | Setting |
|---|---|---|
| Patients with obstructing, locally advanced (ie., with invasion of adjacent structures) colon cancer T4N0/T3N0 high-risk features (high risk-obstructing) | Medical oncologists should offer adjuvant chemotherapy after surgery and fully discussing the risks and benefits with the patient. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with high-risk, obstructing stage II colon cancer | Medical oncologists may offer adjuvant chemotherapy after surgery and fully discussing the risks and benefits with the patient. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with high risk, obstructing stage III colon cancer | Medical oncologists should offer adjuvant chemotherapy after surgery and fully discussing the risks and benefits with the patient. (Strong Recommendation; H) | Maximal |
Table 6. Rectal Cancer Stage I– clinical stage T1 N0
| Population | Intervention | Setting |
|---|---|---|
| Patients with nonmetastatic cT1N0 rectal cancer | General surgeons should perform surgery following total mesorectal excision (TME) principles. (Strong Recommendation; H) | Basic and Limited |
| Patients with nonmetastatic cT1N0 rectal cancer | Surgical oncologists/and or colorectal surgeons should perform TME following standard oncologic principles and, in Maximal settings, using the most advanced techniques. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with select low risk (cT1N0 without adverse features like G3, V1, L1) T1N0 rectal cancers | Surgical oncologists and/or colorectal surgeons may perform local excisional procedures such as TEM. (Moderate Recommendation; I) | Maximal |
Table 7. Rectal Cancer Stage I– clinical stage T2 N0
| Population | Intervention | Setting |
|---|---|---|
| Patients with nonmetastatic cT2N0 rectal cancer | General surgeons should perform surgery following TME principles. (Strong Recommendation; H) | Basic and Limited |
| Patients with nonmetastatic cT2N0 rectal cancer | Surgical oncologists and/or colorectal surgeons should perform TME following standard oncologic principles. (Strong Recommendation; H) | Enhanced |
| Patients with nonmetastatic cT2N0 rectal cancer | Surgical oncologists and/or colorectal surgeons should perform TME following standard oncologic principles, using the most advanced techniques. (Strong Recommendation; H) | Maximal |
Table 8. Rectal Cancer Stage IIA– clinical stage T3 N0
| Population | Intervention | Setting |
|---|---|---|
| Patients with clinically resectable cT3N0 rectal cancer | If TME is feasible, general surgeons should perform surgery following TME principles. (Moderate Recommendation; I) | Basic and Limited |
| Patients with clinically resectable cT3N0 rectal cancer | If surgery following TME principles is not feasible, then clinicians should transfer patients to a higher capacity facility. (Moderate Recommendation; IC-I) | Basic and Limited |
| Patients with clinically resectable cT3N0 rectal cancer at high risk who did not receive neoadjuvant treatment | Surgeons or oncologists may offer basic adjuvant therapy; limited chemotherapy may be offered. (Moderate Recommendation; I) | Basic |
| Patients with clinically resectable cT3N0 rectal cancer at high risk who did not receive neoadjuvant treatment | Surgeons or oncologists may offer basic adjuvant chemotherapy; radiation therapy may be offered in addition to chemotherapy, if available. (Moderate Recommendation; I) | Limited |
| Patients with clinically resectable cT3N0 rectal cancer where there is no indication on MRI that surgery is likely to be associated with either an R2 or an R1 resection | Surgical oncologists and/or colorectal surgeons should perform TME following standard oncologic principles and, in Maximal settings, using the most advanced techniques. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with clinically resectable cT3N0 rectal cancer | Multidisciplinary teams should base decisions regarding neoadjuvant therapy (CRT or SCPRT) on preoperative, MRI-predicted CRM (1mm), EMVI and more advanced T3 substages (T3c/T3d), which define the risk of both local recurrence and/or synchronous and subsequent metastatic disease. (Strong Recommendation; H) | Enhanced and Maximal |
| Patients with clinically resectable pT3N0 rectal cancer at high risk who had surgery and did not receive neoadjuvant treatment | Medical oncologists may offer chemoradiation. (Strong Recommendation; H) | Enhanced |
| Patients with clinically resectable cT3N0 rectal cancer | Treatment decisions regarding neoadjuvant therapy (CRT or SCPRT) should be based on preoperative, MRI-predicted CRM (1mm), EMVI and more advanced T3 substages (T3c/T3d), which define the risk of both local recurrence and/or synchronous and subsequent metastatic disease. (Strong Recommendation; H) | Maximal |
| Patients with clinically resectable cT3N0 rectal cancer, high-risk stage II rectal cancer, and all patients with stage III rectal cancer | Medical oncologists should assess pathologic stage after surgery and should offer adjuvant chemotherapy to reduce the risk of local and systemic recurrence. (Strong Recommendation; H) | Maximal |
Table 9. Early-Stage Colon Cancer Post-Treatment Surveillance
| Population | Intervention | Setting |
|---|---|---|
| Treated patients with Stage II CRC | Medical history, physical exam every 6 months for minimum 3 years. CEA every 6 months for minimum 3 years if available. Chest x-ray and abdominal ultrasound twice in the first 3 years. Colonoscopy once in the first 1–2 years after surgery (if colonoscopy available in local or referral setting). If colonoscopy is unavailable, may perform a double contrast barium enema and/or for left-sided tumors a sigmoidoscopy. (Weak Recommendation; L) | Basic |
| Treated patients with Stage II CRC | Medical history, physical exam and CEA every 6 months for 3–5 years. Abdominal and chest CT scan twice in the first 3 years. Colonoscopy once in the first 1–2 years after surgery (if colonoscopy available in local or referral setting). In cases where a complete colonoscopy was not done at the time of diagnostic workup, a colonoscopy should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1–2 year time point. (Moderate Recommendation; I) | Limited |
| Treated patients with Stage II CRC at standard risk | Medical history, physical exam and CEA every 6 months for 3–5 years. Abdominal and chest CT scan annually for 3 years. Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age. In cases where a complete colonoscopy was not done at the time of diagnostic workup, a colonoscopy should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point. (Moderate Recommendation; I) | Enhanced |
| Treated patients with Stage II CRC at high risk | Medical history, physical exam and CEA every 3–6 months for 5 years. Abdominal and chest CT scan every 6–12 months for 3 years. Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age. In cases where a complete colonoscopy was not done at the time of diagnostic workup, a colonoscopy should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point. (Moderate Recommendation; I) | Enhanced |
| Treated patients with Stage II CRC at standard and high risk | Medical history, physical exam and CEA every 6 months for 3–5 years (high risk for 6 years). Abdominal and chest CT scan annually (high risk every 6–12 months) for 3 years. Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age. In cases where a complete colonoscopy was not done at the time of diagnostic workup, a colonoscopy should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point. (Moderate Recommendation; I) | Maximal |
Table 10. Early-Stage Rectal Cancer Post-Treatment Surveillance
| Population | Intervention | Setting |
|---|---|---|
| Treated patients with rectal cancer | Medical history, physical exam every 6 months for minimum 3 years. CEA every 6 months for minimum of 3 years if available. Chest x-ray and abdominal and pelvic ultrasound twice in the first 3 years. Rectosigmoidoscopy or colonoscopy, (if colonoscopy available in local or referral setting), once in the first 1–2 years after surgery. (Moderate Recommendation; I) | Basic |
| Treated patients with rectal cancer at standard risk | Medical history, physical exam and CEA every 6 months for 3–5 years. CT scan of the chest, abdomen and pelvis twice in the first 3 years. Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age (if colonoscopy available in local or referral setting).a (For Enhanced, for those patients who have not received pelvic radiation) (Moderate Recommendation; I) | Limited, Enhanced, and Maximal |
| Treated patients with rectal cancer at high risk | Medical history, physical exam and CEA every 3–6 months for 5 years. CT scan of the chest, abdomen and pelvis 6–12 months for 3 years. Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age.a (Moderate Recommendation; I) | Enhanced and Maximal |
| Treated patients with rectal cancer who have not received pelvic radiation or who underwent surgery without TME or who have had a positive circumferential resection margin | Digital rectal exam or rectosigmoidoscopy may be performed every 6 months for 3 years based on availability. (Weak Recommendation; L) | Basic |
| Treated patients with rectal cancer at standard risk who have not received pelvic radiation or who underwent surgery without TME or who have had a positive circumferential resection margin | Digital rectal exam or rectosigmoidoscopy should be performed every 6 months for 3 years based on availability.a (Moderate Recommendation; I) | Limited |
| Treated patients with rectal cancer at standard risk who have not received pelvic radiation | A rectosigmoidoscopy should be performed every 6 months for 2–5 years.a (Moderate Recommendation; I) | Enhanced and Maximal |
| Treated patients with rectal cancer at high risk who have not received pelvic radiation or who underwent surgery without TME or underwent endoscopic mucosal dissection, or who have had a positive circumferential resection margin | A rectosigmoidoscopy and/or endoscopic rectal ultrasound should be performed every 6 months for 2–5 years.a (Moderate Recommendation; I) | Enhanced and Maximal |
| Treated patients with rectal cancer, where a complete colonoscopy was not done at the time of diagnostic workup | A colonoscopy, (if colonoscopy available in local or referral setting), or barium enema, should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point. (Moderate Recommendation; I) | Basic |
| Treated patients with rectal cancer at high risk who have not received a complete colonoscopy at the time of diagnosis | A colonoscopy, (if colonoscopy available in local or referral setting) should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point.a (Moderate Recommendation; I) | Limited, Enhanced, and Maximal |
Table 11. Early-Stage Colon Cancer Follow Up (summary)
| Basic | Limited | Enhanced and Maximal | |
|---|---|---|---|
| Medical history, Physical exam and CEA | Every 6 months minimum 3 yrs. (CEA if available) | Every 6 months for 3–5 yrs. | Every 6 months for 3–5 yrs. |
| Imaging | CXR and Abdominal Ultrasound twice in the first 3 yrs. | CT chest, abdomen and pelvis twice in the first 3 yrs. | CT chest, abdomen and pelvis annually for 3 yrs. (High risk q6–12 months) |
| Surveillance Colonoscopy | Once in the first 1–2 yrs. after surgery | Once in the first 1–2 yrs. after surgery | Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age. |
Table 12. Early-Stage Rectal Cancer Follow Up (summary)
| Basic | Limited | Enhanced | Maximal | |
|---|---|---|---|---|
| Medical history, Physical exam (including DRE) and CEA | Every 6 months minimum 3 yrs. (CEA if available) | Every 6 months for 3–5yrs (High risk q3–6 months for 5yrs) | ||
| Imaging | CXR and Abdomino-Pelvic Ultrasound twice in the first 3 yrs | CT chest, abdomen and pelvis twice in the first 3 yrs (High risk q6–12 months) | CT chest, abdomen and pelvis annually for 3 yrs (High risk q6–12 months) | |
| Surveillance Colonoscopy | Rectosigmoidoscopy or Colonoscopy once in the first 1–2 yrs after surgery (if available) | Colonoscopy 1 year after surgery then every 5 years or earlier as clinically indicated up to 75 years of age. | ||
| Standard Risk but did not receive Pelvic Radiation | Digital rectal exam or Rectosigmoidoscopy every 6 months for 3 years (if available) | Rectosigmoidoscopy every 6 months for 2–5 years. | ||
| Incomplete Diagnostic Colonoscopy | Colonoscopy, if available, or barium enema, should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point | Colonoscopy should be done as soon as reasonable after completion of adjuvant therapy and not necessarily at the 1-year time point | ||
