Primary Tumour Surgery for Stage IV CRC Falling in USA

An increase in median relative survival of US patients with stage IV colorectal cancer coincides with falling use of primary tumour resection

medwireNews: US surgeons are increasingly unlikely to choose primary tumour resection (PTR) for patients with stage IV colorectal cancer (CRC), shows research which also reveals an increase in patient survival in recent years.

Overall, 67.4% of the 64,157 patients diagnosed with stage IV colon or rectal cancer between 1988 and 2010 underwent PTR, indicate data from the Surveillance, Epidemiology, and End Results CRC registry.

However, the annual rate of PTR fell significantly between 1988 and 2010, from 74.5% to 57.4%, with a significant difference noted in the annual percentage changes between 1998 and 2001 compared with 2001 and 2010, at –0.41% versus –2.39%.

This reduction in PTR use coincided with a significant improvement in the median 5-year relative survival rate between 1988 and 2009, from 8.6% to 17.8%. The annual percentage change significantly increased from 2.18% between 1988 and 2001 to 5.43% between 1996 and 2009.

These trends in PTR use and survival both “coincided with advances in chemotherapeutic agents that started in 2000”, say George Chang and team, from the University of Texas MD Anderson Cancer Center in Houston.

But writing in JAMA Surgery, they note that “despite the proven benefit of chemotherapy” for controlling symptoms and converting unresectable to resectable disease, more than half of patients in 2010 underwent PTR.

“It appears that current treatment practice may still lag behind evidence-based treatment guidelines and that there is still work needed to translate evidence on the effectiveness of health care decisions into clinical practice”, the team comments.

Multivariate analysis showed that patients were significantly less likely to undergo PTR if they were younger (odds ratio [OR]=0.67 for those aged 76–90 vs 18–49 years), male (OR=0.91) or Black (OR=0.73 vs White patients).

By contrast, patients were more likely to undergo PTR if they were married or divorced than if they were single (OR=1.43 and 1.12, respectively) and if they had well differentiated or moderately differentiated tumours (OR=1.17 vs poorly or undifferentiated tumours).

Compared with patients with right colon tumours, those with left colon disease were significantly more likely to undergo PTR (OR=1.19), while those with rectosigmoid or rectum disease, or unspecified disease were less likely (OR=0.31 and 0.12, respectively).

“Several factors might have led to such an observation, including a higher infection rate after rectal surgery, the complexity of rectal surgery, patient fear of a permanent colostomy if anal function could not be preserved, and improved local control with the use of multimodality therapy”, the researchers comment.

The team concludes: “Despite the availability of more effective chemotherapeutic options, a considerable number of patients with stage IV CRC continue to undergo PTR.”

“Our findings indicate potential overuse of PTR among these patients and highlight a need to better understand the clinical decisions and outcomes associated with that treatment.”

Reference

Hu C-Y, Bailey CE, You N, et al. Time trend analysis of primary tumor resection for stage IV colorectal cancer. Less surgery, improved survival. JAMA Surg 2015; Advance online publication 14 January. doi:10.1001/jamasurg.2014.2253

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