Background: Esophageal carcinoma is a late complication of lye ingestion; patients with lye carcinoma (LC) tend to have a longer survival than patients with primary esophageal carcinoma (PC), however. A younger patient s age, an earlier diagnosis, and scar tissue around the tumor have been suggested as favorable prognostic factors. Aim: to investigate which was the most important prognostic indicator of better survival in LC patients.
Methods: data from 20 patients (11 male, 9 female, median age 59 years) with LC were compared to findings in 2616 patients with PC observed in the last 19 years. LC occurred a median 43 years (range 21 67) after lye ingestion. The amount of scar tissue was measured in the specimen of 7 patients with LC and 9 with PC, matched for sex, age, tumor stage and histological grading, by means of a computerized image analysis system (Zeiss Cires workstation and Kontron frame-grabber) after staining with trichrome Masson.
Results: The female/male ratio was higher among LC patients (45% vs 18%, p=0.002); the median age was similar in the two groups, i.e. 58 (range 38-81) years vs 61 (range 24-90) years. The mean duration of symptoms was longer (though not significantly so) in LC patients (231 ± 56 days) vs PC patients (160 ± 3 days), p:n.s. The amount of fibrotic tissue around the tumor was significantly greater in patients with LC compared to PC patients (LC 35% of fibrotic tissue, PC: 6%, p:0.001.) The resectability rate in the two groups was similar (70% vs 52%, p:n.s.). The post-operative TNM of the 14 resected LC patients was compared to 1365 resected PC patients: LC patients had a greater prevalence of tumors limited to the muscle wall (64% vs 34% in PC patients; p<0.02). In LC patients with tumor limited to the esophageal wall (T1-T2) no positive nodes were found. Conversely, 32% of PC patients with T1-T2 tumor had positive nodes (p< 0.001). Therefore the overall 5-year survival rate for LC resected patients was 57% vs 21% for PC, p=0.005.
Conclusions: the presence of scar tissue around the tumor is the main reason behind the better prognosis in lye-induced esophageal carcinoma, offering protection not only against local spread, but also against nodal dissemination.