- This prospective registry study examined 265 patients who underwent elective surgical resection of stage IV primary colorectal cancer at Massachusetts General Hospital, of whom 35% had metastases resected
- In the curative setting, obesity, duration of surgery ≥180 minutes and open surgery were independent predictors of postoperative complications, whereas obesity and lymph node–positive disease were independent risk factors for reduced survival
- In the palliative setting, risk factors for postoperative complications were age 60 or older and neoadjuvant treatment, and risk factors for reduced survival were ASA score III–IV, preoperative leukocytosis and cardiac or respiratory complications
- The rate of postoperative complications within 30 days was 38.5%, and in the palliative setting, survival was significantly worse in patients who developed complications
- These findings confirm the feasibility of primary tumor resection when metastasis appears to be resectable, but for patients with unresectable metastases, the decision to resect the primary tumor should be made cautiously
A continuing controversy in colorectal cancer treatment is whether to resect the primary tumor when patients have distant metastasis. The National Comprehensive Cancer Network recommends surgery only when such patients have symptoms that may preclude adjuvant therapy, such as bowel obstruction, perforation or excessive bleeding.
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On the other hand, several groups have advocated non-curative resection in asymptomatic patients to prevent emergency procedures. Three recent meta-analyses demonstrated a survival benefit of five to eight months after surgery compared with systemic therapy alone. However, the studies analyzed are potentially limited by selection bias, since younger or healthier patients are more likely to undergo surgery.
By examining a prospective registry, Lieve G. J. Leijssen, MD, researcher with the Massachusetts General Hospital Division of General and Gastrointestinal Surgery, David L. Berger, MD, colorectal and gastrointestinal surgeon at the Mass General Cancer Center, and colleagues confirmed improved survival after resection in patients with advanced colorectal cancer. However, in the Journal of Surgical Oncology, the researchers add that surgery was associated with a high morbidity rate.
The researchers identified 265 patients who underwent elective surgical resection of stage IV primary colorectal cancer at Mass General between 2004 and 2015. In 119 patients (35%) the metastases were deemed resectable because they were confined to the liver, lung or reproductive organs and the patient had an adequate performance status.
In line with previous studies, the postoperative morbidity rate, defined as any surgical or medical complication within 30 days of surgery, was 38.5%. Patients who underwent a rectal procedure were at particular risk of complications:
- Unresectable group: Significantly higher odds of surgical site infections (OR, 11.28), urinary problems (OR, 4.62) and postoperative ileus (OR, 3.46) in patients with rectal cancer than in those with colon cancer
- Resectable group: Significantly higher odds of urinary problems (OR, 10.29) in patients with rectal cancer than in those with colon cancer
Follow-up lasted until April 30, 2018. The median survival was 22.2 months in the unresectable group and 56.7 months in the resectable group, with no significant difference between colon and rectal cancer patients.
Estimated five-year survival rates were statistically comparable in the unresectable and resectable groups:
- Unresectable: 4.9% for colon cancer and 3.8% for rectal cancer
- Resectable: 64% for colon cancer and 57% for rectal cancer
Impact of Complications on Survival
Among patients in the unresectable group, survival was significantly better in those who did not develop postoperative complications:
- One-year survival: 66% in patients with one or more complications vs. 81% in patients who had an uncomplicated treatment
- Three-year survival: 11% vs. 27%
- Five-year survival: 0% vs. 4%
Complications had no significant impact on survival in the resectable group.
Predictors of Postoperative Complications
In the unresectable group, patients with left-sided colon tumors were significantly less likely than those with rectal tumors to develop postoperative complications (OR, 0.30). Independent risk factors for postoperative complications were age 60 or older (OR, 2.18) and neoadjuvant treatment (OR, 2.84).
In the resectable group, independent risk factors for postoperative complications were obesity (OR, 2.88) and duration of surgery ≥180 minutes (OR, 2.53). Completed laparoscopic surgery was a protective factor (OR, 0.33).
Predictors of Survival
Independent risk factors for reduced overall survival were:
- Unresectable group: ASA score III–IV (HR, 1.51), preoperative leukocytosis (HR, 1.77), cardiac complications (HR, 3.75) and respiratory complications (HR, 7.53)
- Resectable group: Obesity (HR, 2.34) and lymph node-positive disease (HR, 3.04)
Guidance for Surgeons
These findings confirm the feasibility of primary tumor resection when metastasis appears to be resectable. For patients with unresectable metastases, the decision to resect the primary tumor should be made cautiously, particularly in individuals who have poor performance status, respiratory comorbidities or cardiac comorbidities. It is worth considering more frequent follow up with such patients.
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