RECENT EXPERIENCE WITH SARCOMATOSIS: LOW VOLUME DISEASE PREDICTS FOR IMPROVED SURVIVAL

Holtz D, Bilimoria M, Mirza N, Feig B, Pisters P, Benjamin R, Patel S, Papadopoulos N, Plager C, Burgess M, Pollock R, Hunt K. (UT MD Anderson Cancer Center, Houston, TX 77030-4095).

The appropriate therapeutic interventions for sarcomas which have disseminated intra-abdominally (sarcomatosis) remain unclear. We examined our recent experience with patients diagnosed with sarcomatosis in order to determine the overall survival and the differences in survival with respect to differing histologies.

Methods: Examination of our prospective sarcoma database revealed 37 patients with a diagnosis of sarcomatosis between January 1996 and December 1998. Clinical and pathologic factors were evaluated and survival was calculated using a Kaplan-Meier Survival Analysis.

Results: A total of 37 patients with a diagnosis of sarcomatosis and a median age of 54 years (range 27-70 years) were registered between 1996 and 1998. Eighteen patients were female and 19 were male. Median time from initial diagnosis of a sarcoma to development of sarcomatosis was 0.9 years (range=0-26 years). Five patients were treated with surgery and chemotherapy while 31 received nonsurgical management (one patient lost to follow-up). Histology was gastrointestinal leiomyosarcoma(GIST) in 19 patients and other histologies in 18 patients. Patients with GIST had similar two-year overall survival when compared to patients with sarcomatosis of other histologies (37% versus 36% respectively, P=0.58). Tumor volume was assessed by findings at surgical exploration or CT scan evaluation and was categorized as low volume disease (<5 cm in diameter or <10 peritoneal nodules) in 10 patients and high volume disease (>5 cm in diameter or >50 peritoneal nodules) in 22 patients (data not available for 5 patients). Patients with low volume disease had an overall two-year survival of 75% compared to only a 14% two-year survival for patients with higher volume disease (P=0.027). Patients with low grade tumor (n=10) had a trend toward longer two-year survival (62% versus 24%) compared to patients with high grade tumors (n=19). With a median follow-up of 2.1 years (range 0.5-26.4 years) 43% of patients died of disseminated sarcoma while 54% remain alive with disease. Of those that died of disease the median time from sarcomatosis to death was 14 months (range 4-42 months).

Conclusion: Despite recent data demonstrating decreased survival for patients with sarcomatosis from leiomyosarcoma, we found no significant difference among patients with GIST or non-GIST sarcomatosis. The overall survival of patients with sarcomatosis remains poor. Volume of disease permits strtification of patients into poor prognosis and better prognosis subsets.