Skip Navigation
Skip to contents

Cancer Res Treat : Cancer Research and Treatment

OPEN ACCESS

Author index

Page Path
HOME > Browse articles > Author index
Search
Gregory S. Zaric 1 Article
The Clinical Significance of Occult Gastrointestinal Primary Tumours in Metastatic Cancer: A Population Retrospective Cohort Study
Malek B. Hannouf, Eric Winquist, Salaheddin M. Mahmud, Muriel Brackstone, Sisira Sarma, George Rodrigues, Peter K. Rogan, Jeffrey S. Hoch, Gregory S. Zaric
Cancer Res Treat. 2018;50(1):183-194.   Published online March 21, 2017
DOI: https://doi.org/10.4143/crt.2016.532
AbstractAbstract PDFPubReaderePub
Purpose
The purpose of this study was to estimate the incidence of occult gastrointestinal (GI) primary tumours in patients with metastatic cancer of uncertain primary origin and evaluate their influence on treatments and overall survival (OS).
Materials and Methods
We used population heath data from Manitoba, Canada to identify all patients initially diagnosed with metastatic cancer between 2002 and 2011. We defined patients to have “occult” primary tumour if the primary was found at least 6 months after initial diagnosis. Otherwise, we considered primary tumours as “obvious.” We used propensity-score methods to match each patient with occult GI tumour to four patients with obvious GI tumour on all known clinicopathologic features. We compared treatments and 2-year survival data between the two patient groups and assessed treatment effect on OS using Cox regression adjustment.
Results
Eighty-three patients had occult GI primary tumours, accounting for 17.6% of men and 14% of women with metastatic cancer of uncertain primary. A 1:4 matching created a matched group of 332 patients with obvious GI primary tumour. Occult cases compared to the matched group were less likely to receive surgical interventions and targeted biological therapy, and more likely to receive cytotoxic empiric chemotherapeutic agents. Having an occult GI tumour was associated with reduced OS and appeared to be a nonsignificant independent predictor of OS when adjusting for treatment differences.
Conclusion
GI tumours are the most common occult primary tumours in men and the second most common in women. Patients with occult GI primary tumours are potentially being undertreated with available GI site-specific and targeted therapies.

Citations

Citations to this article as recorded by  
  • Relationship between metastasis and second primary cancers in women with breast cancer
    Chaofan Li, Mengjie Liu, Jia Li, Xixi Zhao, Yusheng Wang, Xi Chen, Weiwei Wang, Shiyu Sun, Cong Feng, Yifan Cai, Fei Wu, Chong Du, Yinbin Zhang, Shuqun Zhang, Jingkun Qu
    Frontiers in Oncology.2022;[Epub]     CrossRef
  • The Potential Clinical and Economic Value of Primary Tumour Identification in Metastatic Cancer of Unknown Primary Tumour: A Population-Based Retrospective Matched Cohort Study
    Malek B. Hannouf, Eric Winquist, Salaheddin M. Mahmud, Muriel Brackstone, Sisira Sarma, George Rodrigues, Peter K. Rogan, Jeffrey S. Hoch, Gregory S. Zaric
    PharmacoEconomics - Open.2018; 2(3): 255.     CrossRef
  • 9,098 View
  • 140 Download
  • 2 Web of Science
  • 2 Crossref
Close layer

Cancer Res Treat : Cancer Research and Treatment
Close layer
TOP