The survival and clinicopathological differences between patients with stage IIIA and stage II rectal cancer: An analysis of 12,036 patients in the SEER database.
BACKGROUND
Stage IIIA rectal cancer has distinctive oncological features, including limited depth of intestinal wall invasion and early regional lymph node metastasis. We aim to compare survival outcomes and clinicopathological features for stage IIIA rectal cancer with those for stage II rectal cancer.


METHODS
We analyzed patients with stage II or stage IIIA rectal cancer treated with surgery without receiving preoperative radiotherapy based on data from the US Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2003. Survival curves were plotted using the Kaplan-Meier method. Multivariate Cox proportional analyses were utilized to analyze independent prognostic factors for cancer-specific survival (CSS).


RESULTS
We included 12,036 rectal cancer patients (10,132 stage II and 1,904 stage IIIA) from the SEER database. Patients with stage IIIA rectal cancer had smaller tumor size than patients with stage II rectal cancer. A multivariate analysis suggested that compared with patients with stage IIIA rectal cancer, patients with stage II disease were more likely to have more unfavorable CSS (HR 1.195, 95% CI 1.079-1.324, p=0.001). When stage II rectal cancer was further analyzed as stage IIA, IIB and IIC rectal cancer, the multivariate analysis indicated that compared with patients with stage IIIA rectal cancer, patients with stage IIA rectal cancer (HR 1.113, 95% CI 1.003-1.235, p=0.044), stage IIB rectal cancer (HR 1.493, 95% CI 1.267-1.758, p<0.001) and stage IIC rectal cancer (HR 2.712, 95% CI 2.319-3.171, p<0.001) were also more likely to exhibit more unfavorable CSS.


CONCLUSIONS
Patients with stage IIIA rectal cancer had more favorable survival outcomes and smaller tumor size compared with patients with stage II rectal cancer.
Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 20032, People's Republic of China.
Ben
B
Huang
Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 20032, People's Republic of China.
Shaobo
S
Mo
Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 20032, People's Republic of China.
Liang
L
Zhu
Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 20032, People's Republic of China.
Tianhong
T
Xu
Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai 20032, People's Republic of China.
Guoxiang
G
Cai
D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology*; D000368:Aged; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000401:mortality* / Q000473:pathology*; D018426:SEER Program; D016019:Survival Analysis
rectal cancer; stage II; stage IIIA; survival