1590P - The prognostic impact of the putative primary site of breast and ovarian cancers in an unfavorable subset of cancer of unknown primary site

Date 10 October 2016
Event ESMO 2016 Congress
Session Poster display
Topics Pathology/Molecular Biology
Basic Scientific Principles
Presenter Makoto Kodaira
Citation Annals of Oncology (2016) 27 (6): 545-551. 10.1093/annonc/mdw393
Authors M. Kodaira1, K. Yonemori2, T. Shimoi3, A. Shimomura2, M. Yunokawa2, C. Shimizu2, Y. Fujiwara2, K. Tamura2
  • 1Medical Oncology, JIKOKAI Kodaira Hospital, 330-0052 - Toda/JP
  • 2Breast And Medical Oncology, National Cancer Center Hospital, 1040045 - Tokyo/JP
  • 3Breast And Medical Oncology, National Cancer Center Hospital, 104-0045 - Tokyo/JP

Abstract

Background

Specific patient subsets with breast and ovarian cancer contributed to the improved survival of the group in which the primary tumor was found. However, the outcome of presuming primary site of breast and ovarian cancer in patients with CUP is not clear.

Methods

Patients who were diagnosed with an unfavorable subset of CUP and who underwent chemotherapy after referral to the National Cancer Center Hospital from April 2007 to March 2015 were enrolled in this study. The presumed primary site of breast and ovarian cancer was based on the information about histology, immunohistochemistry, and pattern of metastasis. We retrospectively assessed the clinical outcomes of patients with the unfavorable subset of CUP with a putative primary site of breast and ovarian cancer (P-CUP) and the patients with the unfavorable subset of CUP (U-CUP).

Results

A total of 409 patients were diagnosed with CUP and 343 patients were categorized as having the unfavorable subset of CUP. A clinicopathological examination revealed that 40 (11.7%) of the 343 patients had P-CUP and the remaining 303 (88.3%) patients had U-CUP. One hundred thirty-six patients received chemotherapy (22 with P-CUP, and 113 with U-CUP). Regarding the initial treatment, among the 22 patients with P-CUP, 3 received hormonal therapy for breast cancer, and the remaining 19 patients received chemotherapy based on the presumed primary organ (breast, 4; ovaries, 15). One hundred and five patients with U-CUP were treated with conventional platinum-based chemotherapy, and 8 patients received non-platinum drug treatment. The objective response rates were 61.1% for P-CUP (95% confidence interval [CI]: 38.6–83.6) and 41.1% for CUP (95% CI: 31.8–50.4). The median overall survival was 50.0 months for patients with P-CUP and 16.9 months for patients with U-CUP (hazard ratio: 0.32, 95% CI: 0.14–0.69, P =0.004).

Conclusions

In this study, patients with a putative primary site of breast and ovaries had higher response rates and a better prognosis compared with the patients with the unfavorable subset of CUP. It might be reasonable to classify this subset as a new category of the favorable subset in CUP.

Clinical trial identification

Legal entity responsible for the study

National Cancer Center Hospital, Japan

Funding

National Cancer Center Hospital, Japan

Disclosure

All authors have declared no conflicts of interest.