Significance of tumor volume and corpus uteri invasion in cervical cancer patients treated by radiotherapy.

The purpose of this study was to show that in advanced cervical cancer patients treated with curative intent, tumor volume and uterine involvement have independent prognostic value. Eligible patients were those seen at the Peter MacCallum Cancer Centre between December 1995 and June 2001, newly diagnosed with a histologic diagnosis of squamous cell carcinoma or adenocarcinoma of the cervix, FIGO-staged IB-IVA, and having undergone magnetic resonance imaging (MRI) and treated with curative intent. Potential prognostic factors considered were FIGO stage, clinical tumor diameter, histology, age, tumor volume, and corpus invasion status. MRI was used to determine the tumor volume and whether there was invasion of tumor into the corpus uteri. One hundred and seventy-nine patients were eligible for this study. The cut-off date for follow-up was October 2003, one patient was lost to follow-up, and the mean potential follow-up time was 4.5 years (range 0.2-7.7 years). There were 60 (34%), 78 (44%), 34 (19%), and 7 (4%) patients in FIGO stages IB, II, III, and IVA, respectively. The tumors of 107 (60%) patients exhibited corpus invasion. The median tumor volume was 33 mL (range 0.1-200 mL). The four factors, FIGO stage, clinical tumor diameter, corpus invasion, and tumor volume, were all strongly positively correlated (P < 0.001 in each case). The 5-year overall survival (OS) rate for all patients was 55% (standard error = 4%). Of the six factors examined, FIGO stage (P= 0.006), clinical tumor diameter (P= 0.013), corpus invasion (P < 0.001), and tumor volume (P < 0.001) were statistically significantly related to OS duration in unifactor analyses. However, only corpus invasion (P= 0.013) and tumor volume (P= 0.004) were significantly and independently associated with OS in multifactor analyses. In particular, after adjusting for corpus involvement and tumor volume, there was no evidence for any relationship between OS and either FIGO stage (P= 0.49) or clinical tumor diameter (P= 0.58). The results from the analysis of failure-free survival were very similar. We conclude that in patients with advanced cervical cancer, tumor volume and corpus invasion provide important prognostic information over and above that provided by FIGO stage, clinical tumor diameter, histology, and age.