Aims It is still debatable whether a colorectal cancer tumor size affects patients´ prognosis
and outcome. A more clinically relevant and frequently encountered scenario is the
presence of subclinical obstructive mass during endoscopic exam hindering the passage
of endoscope and precluding complete exam. The significance and implications of this
finding were not fully investigated, and will be addressed in this study.
Methods In this retrospective cohort study we reviewed endoscopy, surgery, pathology and
oncology reports of patients diagnosed with colorectal cancer over a 10-year period
(2007–2016). Patients with finding of obstructive tumor at endoscopy were compared
to those with non-obstructive tumors. We compared surgical stages, histologic grades
and overall survival between both groups. We performed multivariate analysis to identify
independent risk factors associated with advanced CRC stage at diagnosis.
Results 144 patients had obstructive colonic tumors while 254 had non-obstructive tumors
and constituted the control group. Obstructive colon cancer group was significantly
associated with advanced tumor stage (Stage 3 or above) at diagnosis compared to the
non-obstructive controls (69% Vs. 42%, OR = 3.018, 95%CI = 1.951–4.670; P < 0.01).
Likewise, in terms of histologic grade, more patients in the obstructive group were
classified as moderate to poorly differentiated compared to controls (64.5 % vs. 38.4%;
P < 0.001). Patients with obstructive tumors were significantly associated with decreased
one (77.8% vs. 86%; P = 0.01), three (63.6% vs.77.4%; P < 0.01) and five years (53.4%
vs. 67.3% vs.; P < 0.01) overall survival. Increased overall mortality was observed
in survival curves of patients with obstructive tumors along all follow-up period
compared to non-obstructive controls.
Conclusions Even in the absence of clinical sequela, obstructive colorectal cancer at endoscopic
level may be associated with higher stage at diagnosis and reduced overall survival.
Further prospective studies are warranted to confirm these findings and address their
implication on patients´ management.
