SMALL CELL CANCER OF THE RECTUM: A NATIONAL CANCER DATABASE ANALYSIS OF MULTIMODAILTY TREATMENTS AND THEIR IMPACT ON SURVIVAL
Madhuri Badrinath*, Pujitha Kudaravalli, Danning Huang, Amit Goyal, Alina Basnet, Uma K. Murthy
Gastroenterology, SUNY Upstate Medical University, Syracuse, NY
Background: Rectal small cell cancer (rSCC) is an uncommon malignancy of rectum. Significant evidence to support multimodality treatment strategies is lacking. Treatment recommendations are extrapolated from studies of pulmonary and non pulmonary SCC.
Aim: To examine the National Cancer Database (NCDB) for treatment-trends of rSCC to include surgery, chemotherapy, radiation, combination therapies and their effect on survival.
Methods: Retrospective review of rSCC patients in NCDB, (2004-2018), > 18y old, stage I-III. Treatments: Group (Gp) A- Surgery alone; Gp B-Surgery+Chemo; Gp C- Surgery+ Chemo+ XRT; Gp D- Chemo alone; Gp E- XRT alone. Univariate analyses comparing variables in the 5 different treatment groups were performed. Multivariate Cox regression model and Kaplan Meier (KM) analysis was used to assess survival.
Results: 1801 patients were identified with rSCC out of 228,213 patients with rectal cancer (0.7%). Equal distribution of males and females was observed. Table 1 describes univariate analysis of variables of significance. Surgery alone arm (Gp A) had significantly more patient numbers, smaller tumor sizes, lower grades and stage than other groups. No significant differences were observed in patient education, income, distance from treatment center, type of facility (community, academic, integrated network cancer programs) in the treatment groups. Practice trends showed that use of chemotherapy alone increased over the 15 years of the study while patients receiving surgery alone declined in the last 5 years (table 1).
Unadjusted Kaplan- Meier survival curves, (Fig 1), showed an overall significant benefit of Gp A (surgery alone). However, Multivariate Cox regression with adjusted hazard ratio, showed that Gp C (surgery+chemo+XRT) had significant survival advantage over surgery alone, aHR 1.732, 95% CI (1.181-2.542) p = 0.0050. Limitations of this registry study include variation in treatment groups, lack of randomisation, physician bias, and patient choice.
Conclusion: In this observational study, multimodality treatment of surgery, radiation and chemotherapy provided survival advantage over surgery alone for rSCC. However, treatment practice-trends during 15 years (2004-2018) showed increasing use of chemotherapy and declining surgery.
Table 1: Univariate Analysis of Patient, Tumor & Clinical Variables in the 5 Treatment Groups
Figure 1: Kaplan Meier Overall Survival Curves between the 5 Treatment Groups
Back to 2023 Abstracts