Differences in Prognosis between Synchronous and Metachronous Metastatic Breast Cancer

Abstract

Background and aim: There are many previous articles that studied the relationship of prognostic factors with metastatic breast cancer, as they provided us with important information on factors related to the nature of the tumor itself, and others related to the patient. Also, the prognostic factors differ with the nature of the metastasis and its time of occurrence. We aim to identify the differences in prognosis between synchronous and metachronous metastatic breast cancer.   

Patients and Methods: We identified women in Al-Bairouni-University Hospital with metastatic breast cancer (MBC) diagnosed between January 2008 and December 2010. 1^st time to progression (TTP) was calculated for metachronous versus synchronous patients. Survival rates and median TTP After metastasis diagnosis were determined using the Kaplan-Meier method and prognostic factors were determined in a Cox Proportional Hazard model.

Results: We identified 350 patients, median TTP (mTTP) was longer for synchronous versus metachronous MBC (14 months for SMBC versus 8 months for MMBC) (P=0.0001). While TTP for patients with synchronous MBC is longer in positive hormonal receptor HR= 0.63 (0.40-0.99) (P = 0, 046) and was affected negatively by high grade of tumor HR= 3.83 (1.12-13.03) (P = 0.032). Otherwise, TTP for patient with metachronous MBC is to a larger extent associated with factors intrinsic to the patients and tumor such as performance status HR=3.6 (1.38-9.34) (P =0.009), high grade of tumor HR=2.30 (1.03-5.11) (P = 0.042) and high number of metastatic site HR=7.12(0.90-56.30) (P =0.063).

Conclusion: TTP with synchronous metastases is longer than with metachronous metastases and the prognostic factors affect differently between two groups which requires special approach to each of them in terms of prognosis and treatment.