Objective: To clarify the biologic behavior of esophageal signet ring cell (SRC) carcinomas of the esophagus and gastroesophageal junction (GEJ). To evaluate the accuracy of pretreatment biopsies in diagnosing true SRC carcinoma.
Background: In contrast with gastric cancer, little is known about the biologic behavior and prognosis of SRC.
Methods: All adenocarcinomas (ADC) of the esophagus and GEJ-patients undergoing primary resection between 1990 and 2009 were included (n = 920). Specimens containing SRCs (n = 114) were classified according to World Health Organization criteria (>50% SRC or <50% SRC).
Results: Thirty-two patients showed more than 50% SRC and 71 patients showed less than 50% SRC. Overall cancer-specific 5-year survival was worse for SRC (22.4%, P < 0.0001) and for SRC > 50% (13.6%, P = 0.0001) compared with ADC. Complete resection was achieved in 86.5% of patients (n = 697) in ADC, 69.5% (n = 57) in SRC < 50%, and 78.1% (n = 25) in SRC > 50% (vs ADC, respectively, P < 0.0001 and P = 0.1801). In 379 pN + R0 patients, the median number of positive lymph nodes was comparable between ADC and SRC < 50% (4 vs 5, P = 0.207) or SRC > 50% (4 vs 8, P = 0.077). Compared with ADC, SRC > 50% showed more pN3's (30% vs 61%, P = 0.006), higher recurrence (56% vs 42% for ADC, P = 0.003), and local-regional recurrences (29% vs 16%, P = 0.002). Pretreatment biopsies were unreliable to define the presence of SRC > 50% (sensitivity = 56.3%, positive predictive value = 43.9%).
Conclusions: SRCs are aggressive neoplasms associated with poorer prognosis than other ADCs after primary esophagectomy. Because our data suggest that pretreatment biopsies failed to reliably define presence of SRC > 50%, presence of SRCs in pretreatment biopsies seems to be of no use to define treatment strategy or prognosis.