Study Reports Highly Skilled Surgeons Significantly Reduce Death From Colon Cancer

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To improve long-term survival odds, individuals with early-stage colon cancer should have their surgery performed by highly skilled surgeons. In a study that used video assessment, surgeons with highly ranked skills gave their patients a 69% lower risk of dying at 5 years as compared with their less-experienced colleagues, according to researchers from Northwestern University Feinberg School of Medicine.1

“A less-skilled surgeon may not remove as many lymph nodes, potentially leaving behind cancer.”
— Brian Brajcich, MD, MS

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“We evaluated videos submitted by surgeons and assigned them scores based on technical skill—high, middle, and low. Patients with higher-skilled surgeons had significantly improved overall survival over the long term. This difference persisted past the immediate postop period, suggesting there’s something in how surgeons are treating the underlying disease,” said first author Brian Brajcich, MD, MS, a surgical resident and research fellow at Northwestern.

“While somewhat obvious, this is still pretty mind-blowing,” commented senior investigator Karl Bilimoria, MD, Professor of Surgery at Northwestern and Director of the Surgical Outcomes and Quality Improvement Center there. “The long-term effect is considerable.”

Previous studies have found fewer short-term complications, such as colon leak or bleeding, after surgery performed by a highly skilled surgeon.2,3 Although these studies have shown the importance of surgical skill, the authors believe theirs is the first study to associate surgical skill with long-term oncologic outcomes.

“Surgical experience and volume of procedures are good markers for technical skill.”
— Karl Bilimoria, MD

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The findings were presented virtually at the Commission on Cancer Annual Meeting and recently published in JAMA Oncology.1

About the Study

Surgeons were recruited from the Illinois Surgical Quality Improvement Collaborative in 2016 and enrolled in a video-based technical skills assessment program. All surgeons submitted one representative video of a laparoscopic right hemicolectomy they had performed. Videos were reviewed by 12 or more surgeons, including 2 colorectal surgeons with video-evaluation experience.

Skill scores were assigned using the American Society of Colon and Rectal Surgeons Video Assessment Tool, which evaluates such factors as fluidity of motion and step-specific skills for resection. A mean skill score per clinicians was calculated from the raters; these scores were analyzed separately by tercile and as a continuous variable.

Patients who underwent any minimally invasive colectomy for stage I to III colon cancer of epithelial origin were identified in the National Cancer Database. Those treated between 2012 and 2017 were extracted by the study’s participating surgeons. The primary outcome was overall survival after surgery, and the secondary outcome was the number of lymph nodes harvested.

In total, 609 patients at 11 hospitals underwent laparoscopic colectomy by 1 of 15 participating surgeons (9 colorectal and 6 general surgeons).

Survival According to the Skill of the Surgeon

Overall survival differed among skill terciles. The 5-year survival was 79% for patients of highly skilled surgeons, 55% for those whose surgeons had mid-level skills, and 60% for patients of the lowest-skilled surgeons. When adjustments were made for patient characteristics, survival was improved for the high-skill vs low-skill tercile (hazard ratio [HR] = 0.31; P < .001), the study found.


  • A study from Northwestern evaluated surgeons’ skill level in performing resection for early-stage colon cancer.
  • By video assessment, surgeons were ranked as having high, middle, or low skill levels.
  • Patients whose surgeons were in the highest skill tercile had a 69% reduced risk of dying at 5 years (P < .001).
  • The association held when investigators controlled for early postoperative deaths, suggesting it was not related to prevention of complications.

Each 0.1-point skill score increment was associated with a higher likelihood of survival (HR = 0.90; P = .01). A sensitivity analysis excluding 90-day mortalities demonstrated similar results. The association between skill and outcomes was strongest among patients with stage II disease: mortality was reduced by 86% in the analysis of high vs low skill (P < .001) and by 88% for middle vs low skill (P < .001).

Dr. Bilimoria acknowledged the small study size but said this makes the findings “compelling” and “even more impressive.”

Why the Difference?

According to Dr. Bilimoria, it could be that highly skilled surgeons are apt to remove more of the potentially involved lymph nodes, thus improving their patients’ prognoses. In the study, the mean number of lymph nodes examined was 23.9 for the high-skill tercile, 21.2 for the middle-skill tercile, and 20.3 for the low-skill tercile.

“It’s important to take out the entirety of the tumor burden, and that involves removing lymph nodes associated with that [diseased] portion of the colon,” he said. “Higher-skilled surgeons did do that. Numerically, it’s not that much of a difference, but it was more, giving some insight to suggest that may be part of the mechanism.”

“A less-skilled surgeon may not remove as many lymph nodes, potentially leaving behind cancer,” Dr. Brajcich added. “Patients who would benefit from chemotherapy after surgery won’t receive it if we don’t know the cancer has spread to the lymph node.”

Also, although surgery performed in expert hands is less likely to result in complications, the association between skill and survival persisted in the current study when excluding early postoperative deaths. This suggests the findings are not solely attributable to mortality from surgical complications, Dr. Bilimoria said.

Other possibilities are that highly skilled surgeons happened to operate on patients with less-aggressive tumors, “but we adjusted for that and still found an effect,” he said. It is also possible they adhere better to treatment guidelines, although the authors found nothing to suggest this, nor that they were more likely to recommend chemotherapy to their patients, he added.

Patients Should Ask About Surgeons’ Experience

According to Dr. Bilimoria, surgical skills are associated with experience. Patients should ask how many procedures of the relevant type their surgeon has performed.

“Surgical experience and volume of procedures are good markers for technical skill. You can triangulate this with recommendations from referring physicians and others in the community…. That’s about as good as patients can do now,” Dr. Bilimoria commented. “General surgeons, colorectal surgeons, and surgical oncologists all do colon cancer surgery, and there can be excellent cancer surgeons in each of those fields.”

The participants found video assessment to be an incredible learning tool. “The surgeons loved this…. It’s transformational to watch your own video and receive feedback,” he said. Dr. Bilimoria and his team will expand this colon surgery–based research into other tumor types.

DISCLOSURE: Dr. Brajcich and Dr. Bilimoria reported no conflicts of interest.


1. Brajcich BC, Stulberg JJ, Palis BE, et al: Association between surgical technical skill and long-term survival for colon cancer. JAMA Oncol. October 30, 2020 (early release online).

2. Birkmeyer JD, Finks JF, O’Reilly A, et al: Surgical skill and complication rates after bariatric surgery. N Engl J Med 369:1434-1442, 2013.

3. Stulberg JJ, Huang R, Kreutzer L, et al: Association between surgeon technical skills and patient outcomes. JAMA Surg 155:960-968, 2020.

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