Do Bone Metastases from Gastrointestinal Cancers Produce Similar Response Rates Following Radiotherapy When Compared to Bone Metastases from Other Primary Cancers?

Abstract

Purpose There has been limited report investigating whether painful bone metastases from gastrointestinal (GI) cancers produce similar response rates to palliative radiation therapy (RT) when compared to bone metastases from other primary cancer sites. The present study evaluated the response rates of symptomatic bone metastases from GI cancers following palliative outpatient RT in the Rapid Response Radiotherapy Program (RRRP). Methods and Materials Sixty-nine patients with bone metastases from GI primaries who received palliative RT in the RRRP clinic from 1999-2006 were identified. Thirty-one of these patients were extracted from an RRRP database that employed the Edmonton Symptom Assessment Scale (ESAS) from 1999-2003. The remaining 38 patients were evaluated from an RRRP database that employed the Brief Pain Inventory (BPI) from 2003-2006. Eligibility criteria for encryption in the aforementioned RRRP databases and collected patient demographic information (age, gender, primary cancer site, and Karnofsky Performance Status) were identical. Response rates for this cohort of metastatic GI patients were then compared to 479 patients receiving palliative RT for bone metastases from other primary cancer sites. Pain scores, employing the ESAS and BPI, as well as analgesic consumption were collected at baseline and by telephone follow-up at 4, 8, and 12 weeks after RT for all patients. Complete response (CR), partial response (PR) and overall response (CR+PR) were evaluated according to International Consensus Endpoints. Results Assessment of the 69 patients with metastatic GI cancers revealed CR, PR, and CR+PR rates of 18%, 42%, and 61% at 4 weeks, 22%, 35%, and 57% at 8 weeks and 50%, 21%, and 71% at 12 weeks, respectively, for evaluable patients. The 479 evaluable patients with metastatic cancer from other primary cancer sites had CR, PR, and CR+PR rates of 25%, 27%, and 51% at 4 weeks, 26%, 22%, and 48% at 8 weeks, and 22%, 29%, and 51% at 12 weeks, respectively. There were no statistically significant differences in RT response rates for bone metastases from GI cancers versus the other primary cancer sites. Conclusion Bone metastases from GI cancers demonstrate similar response rates following palliative RT when compared to other primary cancer sites. Patients with symptomatic bone metastases from GI malignancies should be referred for palliative radiotherapy as readily as patients with osseous metastases from other primary cancer sites. Keywords Bone metastases, gastrointestinal cancers, palliative radiotherapy, response.