Genome-wide investigation of multifocal and unifocal prostate cancer-are they genetically different?

Prostate cancer is widely observed to be biologically heterogeneous. Its heterogeneity is manifested histologically as multifocal prostate cancer, which is observed more frequently than unifocal prostate cancer. The clinical and prognostic significance of either focal cancer type is not fully established. To investigate prostate cancer heterogeneity, the genetic profiles of multifocal and unifocal prostate cancers were compared. Here, we report observations deduced from tumor-tumor comparison of copy number alteration data of both focal categories. Forty-one fresh frozen prostate cancer foci from 14 multifocal prostate cancers and eight unifocal prostate cancers were subjected to copy number variation analysis with the Affymetrix SNP 6.0 microarray tool. With the investigated cases, tumors obtained from a single prostate exhibited different genetic profiles of variable degrees. Further comparison identified no distinct genetic pattern or signatures specific to multifocal or unifocal prostate cancer. Our findings suggest that samples obtained from multiple sites of a single unifocal prostate cancer show as much genetic heterogeneity and variability as separate tumors obtained from a single multifocal prostate cancer.

Palliative treatment of unresectable metastatic colorectal cancer

IMPORTANCE OF THE FIELD

Treatment options for metastatic colorectal cancer (mCRC) patients have rapidly increased in the past years, but 50 - 70% of mCRC patients are still unlikely to undergo radical resection of metastases and are candidates for palliative therapy only.

AREAS COVERED IN THIS REVIEW

Oxaliplatin and irinotecan have widened the chemotherapy alternatives available in this setting and effective targeted agents against vascular endothelial growth factor and epidermal growth factor receptor have further improved treatment efficacy. This review covers the main areas of debate in the optimal treatment of unresectable mCRC patients, focusing on the implications for everyday clinical practice and future research of the most relevant clinical trials and molecular investigations published from 1999 to 2009.

WHAT THE READER WILL GAIN

Insights into treatment individualization strategies are provided in the review.

TAKE HOME MESSAGE

'One size fits all' can not longer be considered an adequate approach to unresectable mCRC, and treatment with both chemotherapy and biologic agents should be guided by prognostic and predictive factors in order to maximize the benefit while reducing futile toxicities.

Treatment in advanced colorectal cancer: what, when and how?

Treatment of advanced colorectal cancer (CRC) increasingly requires a multidisciplinary approach and multiple treatment options add to the complexity of clinical decision-making. Recently novel targeted therapy against angiogenesis and epidermal growth factor receptor completed a plethora of phase III studies. The addition of bevacizumab to chemotherapy improved the efficacy over chemotherapy alone in both first and second line settings, although the magnitude of benefit may not be as great when a more optimal chemotherapy platform is used. Studies performed thus far did not address conclusively whether bevacizumab should be continued in subsequent lines of treatment. Anti-angiogenesis tyrosine kinase inhibitors have not shown any additional benefit over chemotherapy alone so far. Although some benefits were seen with cetuximab in all settings of treating advanced CRC, K-ras mutation status provides an important determinant of who would not benefit from such a treatment. Caution should be exercised in combining anti-angiogenesis with anti-EGFR strategy until further randomised data become available. In this review, we have focused on the implications of these trial results on the everyday management decisions of treating advanced CRC.