Carcinoma of unknown primary site (CUPS): case series.

Abstract

Background:Carcinoma of unknown primary sites(CUPS)are group of malignancies which present with widespread metastasis without an identifiable primary.3 -5% of all malignancies can present as CUPS. The clinical behavior of these cancers is usually aggressive and prognosis remains poor.

Materials and methods:From January 2023 toaugust 2025,total 19 cases of CUPS were registered in our department for whom the data were collected and analyzed.

Results: Median age at presentation of our patients was 51 years(27 -75 years). 42.1 %( n=8) were females and 57.9 %( n=11) were males. Mean ECOG PS of patients was 2±1.1. Median number of sites involved were 2(1-5).In 26.3%(n=5) patients site of biopsy was lymphnode,21%(n=4),from liver and 10.5%(n=2) were diagnosed by fluid cytology . Morphologically 63.2% (n=12) biopsies were adenocarcinoma,15.8%(n=3) poorly differentiatedcarcinoma,10.5%(n=2) poorly differentiated squamous cell carcinoma,5.3%(n=1) each as poorly differentiated adenocarcinoma and adenoid cystic carcinoma.

After immunohistochemistry (IHC) amongst the 12 adenocarcinoma patients CK7 was positive in 58.3%(7/12),CK20, PanCK in41.6%(5/12)each,CK19in25%(3/12)andCDX2andTTF1in8.3%(1/12).

Poorly differentiated squamous cell carcinoma and adenoid cystic carcinoma histology had 100% P63 positivity. Poorly differentiated carcinomas showed PanCK positivity in 66.6%(n=2),EMA and TTF1 positivity in 33.3%.PET CT was done in 15.7 %( n=3).Primary was apparent in only 2 out of 19 cases (10.5%).After diagnosis 11 patients received chemotherapy, 2 patients received Radiotherapy (1 palliative and 1 radical dose) and 3 patients underwent surgery. Among 11 patients who received chemotherapy median number of chemotherapy cycles given was 4(1-7). 45.4% (n=5) received gemcitabine based chemo, 36.3 %( n=4) paclitaxel and carboplatin, 18 %( N=2) received capecitabine and oxaliplatin.36.3%(N=4)completed the desired number of chemotherapy cycles with 50% CR and 50% PR rates.3 out of 8 patients who were not candidate for chemotherapy received empiricalgeftinib. Median follow of our study was 11.4 months with median progression free survival (PFS) of 6.7±3.2 months (95% CI 0.37 -13.0), median overall survival (OS) 6.9±3.2 months (95%CI 0.57 -13.2).