To study the clinico-pathological profile and treatment outcome in cancer of unknown primary in a tertiary care institution

Abstract

Background: Also known as unknown primary tumour (UPT) is an intriguing clinical phenomenon found in approximately 5% of all newly diagnosed patients with cancer.

OBJECTIVES: To study the incidence, clinical presentation, histology, treatment modalities used frequently and lacunae in not establishing the diagnosis of primary.

STUDY DESIGN: Retro-prospective study design between January 2014 to December 2018.

PARTICIPANTS: 650 patients of cancer of unknown primary were enrolled in this study. After going through various investigations, primary of 387 patients were detected who were excluded from this study. Primary could not be detected in 263 patients even after going through comprehensive work up and radiological imaging and henceforth these were taken up for this study.

METHODS: Demographics, imaging, pathology and treatment data were analyzed from the case records retrospectively between 1^st January 2014 to June 2017. The data was collected prospectively between 1 July 2017 to 30 December 2018. Patients with histo-pathological evidence of metastatic lesion were included and patients whose primary were detected after comprehensive work-up were excluded from this study.

RESULTS: Incidence of unknown primary was 0.65 per 1 lakh population, majority of the patients were from district Srinagar (22.1%) , majority of the patients were in the age group of 61-80 years (47.1%) , male to female ratio was 1.45: 1, abdominal pain (29.7%) and bone pain (20.5%) were the most common clinical presentation, PET scan detected primary in 12 out of 33 patients (36.36%) , abdominal CT scan detected primary lesion in 156 out of 650 patients, adenocarcinoma was the most common histology (58.6%) , external beam radiotherapy was the most common mode of treatment (12.5%) , median survival of these patients was 6-12 months.

CONCLUSION: The lacunae in not detecting the primary in these patients could be that basic investigations like endoscopy, colonoscopy, bronchoscopy, PET scan, IHC markers were not performed by many patients due to reasons not clearly established. As many of these patients came with multiple sites of metastasis and had low performance score on admission, many such patients died even before going through thorough workup and investigations.

IMPLICATIONS: It is recommended that patients should be made aware about the benefit of early detection of primary lesion by subjecting them to all basic investigations, which henceforth would lead to better management and early treatment, thus better survival of these patients. It is recommended that all IHC markers should be made available in our hospital for better assessment and hence better management of these patients. Counselling and education of these patients remains an important aspect that should be taken care of.