Introduction
Rectal carcinoid tumors are rare but the second most common carcinoid in the gastrointestinal tract. They are usually found incidentally during endoscopic or rectal examination. They do not often produce carcinoid syndrome like manifestations although they may manifest as rectal bleeding. Rectal carcinoid patients also have a higher morbidity for other cancers such as stomach, small intestine, or secondary lung cancer.
Methods
We retrospectively explored factors associated with survival in Veterans with rectal carcinoid tumors over a ten-year period from 2007-2017 using the National Veterans Affairs Cancer Cube Registry using specific histological ICD-03 coding. We identified 1110 cases of rectal carcinoid. Chi-squared tests were used for statistical analysis.
Results
Regarding age distribution in our cohort, there were 2.61% of patients ages 40-50 group, 14.0% in the 50-60 age group, 41.5% in the 60-70 age group, and 40.7% above ages 70. There was a higher proportion of rectal cancer in stage 1 compared to other stages (86.3%). The majority of diagnoses occur after age 50 (89.8%). A higher proportion of rectal carcinoid was identified in the 60-70 years category compared to <60 and >70 years old. In the general VA population, there are 80.2% White and 12.8% Black patients. We found a higher proportion of rectal carcinoid in Black patients (47.8%) over White patients (42.8%, p=0.02), which differs significantly from the racial makeup of the VA population (12.8% Black vs 80.3% White). Looking at survival time based on diagnosis, it is notable that 82.7% of individuals survive longer than 5 years when the diagnosis is made in ages 50-60 when compared to 68.7% when the diagnosis is made between ages 60-70 (p<0.001).
Conclusions
Our data is consistent with the SEER data in that the incidence and prevalence of rectal carcinoid are higher in Black patients compared to White patients. Further analysis into reasons for this racial disparity may prove beneficial to our understanding of this malignancy in the Veteran population. Further research is needed to determine whether diagnosis at a younger age offers a survival advantage in rectal carcinoid.