Practice patterns and long-term survival for early-stage rectal cancer

Abstract

Purpose: Standard of care treatment for most stage I rectal cancers is total mesorectal excision (TME). Given the morbidity associated with TME, local excision (LE) for early-stage rectal cancer has been explored. This study examines practice patterns and overall survival (OS) for early-stage rectal cancer.

Methods: All patients in the National Cancer Data Base diagnosed with rectal cancer from 1998 to 2010 were initially included. Use of LE versus proctectomy and use of adjuvant radiation therapy were compared over time. Adjusted Cox proportional hazards models were used to compare OS based on treatment.

Results: LE was used to treat 46.5% of patients with T1 and 16.8% with T2 tumors. Use of LE increased steadily over time (P < .001). LE was most commonly used for women, black patients, very old patients, those without private health insurance, those with well-differentiated tumors, and those with T1 tumors. Proctectomy was associated with higher rates of tumor-free surgical margins compared with LE (95% v 76%; P < .001). Adjuvant radiation therapy use decreased over time independent of surgical procedure or T stage. For T2N0 disease, patients treated with LE alone had significantly poorer adjusted OS than those treated with proctectomy alone or multimodality therapy.

Conclusion: Guideline-concordant adoption of LE for treatment of low-risk stage I rectal cancer is increasing. However, use of LE is also increasing for higher-risk rectal cancers that do not meet guideline criteria for LE. Treatment with LE alone is associated with poorer long-term OS. Additional studies are warranted to understand the factors driving increased use of LE.

Fig 1.

CONSORT diagram. LE, local excision.

Fig 2.

Changes in use of local excision (LE) to treat rectal cancer over time (patients who received neoadjuvant therapy excluded) by (A) disease stage and (B) subtype of stage I tumors. LE is considered standard-of-care therapy only for select patients with well or moderately differentiated T1N0 rectal cancers.

Fig 3.

Adjuvant radiation therapy use for stage I rectal cancers by T stage and type of surgical procedure. LE, local excision.

Fig 4.

Adjusted overall survival by treatment group for T1N0 tumors from (A) 1998 to 2005 (n = 11,528) and (B) 2003 to 2005 (includes comorbidity adjustment; n = 4,295) and for T2N0 tumors from (C) 1998 to 2005 (n = 11,564) and (D) 2003 to 2005 (includes comorbidity adjustment; n = 3,545). HR, hazard ratio.