[736] Bone Marrow Micrometastases in Esophagogastric Cancer – 10-Year Follow-Up Confirms Prognostic Significance

Paul Ryan, Heidi Furlong, Conleth Murphy, Finbarr O'Sullivan, Thomas Walsh, Gerald C O'Sullivan. Bon Secours Hospital, Cork, Ireland; James Connelly Memorial Hospital, Dublin, Ireland; University College Cork, Cork, Ireland; Mercy University Hospital, Cork, Ireland

Background: A majority of esophagogastric cancer (EGC) patients with potentially curative R0 resections succumb to metastatic (haematogenous spread) disease. Current pathologic staging guidelines do not include assessment systemic micrometastatic disease. We present 10-year outcome data of EGC patients with rib marrow examined for micrometastases correlated with treatment and conventional pathologic tumor staging.
Design: With multi-institutional research ethics board approval 77 patients with localized oesophagogastric tumors having radical en-bloc oesophagectomy were followed until death or for 10 years, with >50% patients receiving neoadjuvant (5-fluorouracil/cisplatin-based) chemoradiotherapy (CRT) and the remainder being treated with surgery alone (SO). Posterior rib segments were excised at thoracotomy prior to tumor manipulation. Marrow flushed from the rib segment was enriched for mononuclear cells and stained using a monoclonal anti-cytokeratin 18 antibody. Standard demographic and pathologic parameters were recorded and patients were followed for a mean 10.04 years. Disease recurrences and all deaths in the follow-up period were recorded.
Results: No patients were lost to follow up and 46 EGC-related and 10 non-EGC related deaths occurred. The identifiable prognostic determinants were lymph node positivity, the presence of bone marrow micrometastases and neoadjuvant chemotherapy. Lymph node positivity was a significant predictor of poorer disease specific survival (DSS) in both CRT and SO patients. Multivariate Cox model analysis of risk showed bone marrow micrometastasis positivity differentiated low and high risk groups among SO but not CRT patients. Taking these groups as a whole and allowing for lymph node status micrometastasis positivity increases risk of death in all SO patients but also in lymph node negative CRT patients. The overall contribution of micrometastasis positivity to DSS is significant using likelihood ratio tests (p = 0.022).
Conclusions: Bone marrow micrometastases provide contributory prognostic data in lymph node negative EGC patients and consideration should be given to routine examination for same. Systemic micrometastic disease (bone marrow micrometastases) continues to provide a window on the metastatic process and may be used to refine pathologic staging of EGC to improve outcome prediction.
Category: Gastrointestinal

Monday, March 19, 2012 1:00 PM

Poster Session II # 84, Monday Afternoon


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