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ECC Roundup: Breast Conservation Benefit Varies by Age

— And other reports from the European Cancer Congress

MedpageToday

Older patients with breast cancer and those with significant comorbidities may benefit more from breast-conserving therapy (BCT) compared with mastectomy, according to a study reported at the in Amsterdam.

Analyses of breast cancer-specific survival (BCSS) among 130,000 patients in The Netherlands with early breast cancer (T1-2 N0-2 M0) consistently yielded larger reductions in the hazard ratio for patients 50 and older versus younger patients treated with BCT compared with mastectomy. The differences held up in analyses of patients treated during two time periods (1999 to 2005 and 2006 to 2012).

For the earlier time cohort, hazard ratios were 0.73, 0.77, and 0.69 by age groups 50-65, 66-70, and >75. During the second time period the hazards were 0.78, 0.72, and 0.66. For women <40 and 40-49, the hazards were 0.83 and 0.80 during the first cohort and 0.84 and 0.91 during the later cohort.

An analysis of overall survival yielded similar results favoring BCT for older patients in both cohorts, said , of the University of Twente in Enschede, The Netherlands.

The benefits of BCT among patients with comorbid conditions were more pronounced during the second time cohort, which reflected improvements in adjuvant systemic therapy. The hazard ratio for BCSS was 0.84 in favor of BCT for women with no significant comorbidities and 0.60 for patients with comorbid conditions.

"We would like to emphasize that these results do not mean that mastectomy is a bad choice," Siesling said in a statement. "Our study showed that BCT is at least as good as mastectomy and that some patients might benefit more than others from BCT in the future."

Studies conducted as far back as the 1980s demonstrated comparable survival with BCT and mastectomy for early breast cancer. Whether subgroups of patients might benefit more from BCT remained unclear.

Immunotherapy in Previously Treated Bladder Cancer

Patients with previously treated urothelial cancer lived a median of about 3 months longer if they received pembrolizumab (Keytruda) rather than chemotherapy, a phase III randomized trial showed.

The difference (10.3 versus 7.4 months) represented a 27% reduction in the hazard ratio (P=0.0022). The trial, which involved 542 patients with progressive disease after first-line platinum-based chemotherapy, failed to meet the second primary endpoint of progression-free survival (median PFS 2.1 versus 3.3 months, HR 0.98, P=0.42).

Pembrolizumab led to a significantly higher objective response rate (21.1% versus 11.4%, P=0.0011) and was associated with fewer side effects of any grade (60.9% versus 90.2%) and with fewer grade 3-5 treatment related adverse events (15.0% versus 49.4%). Investigators could choose from paclitaxel, docetaxel, or vinflunine as the chemotherapy comparator.

"The median duration of response for patients who responded to pembrolizumab has not been reached, while the median duration of response for patients who responded to chemotherapy was only 4.3 months," , of the National Cancer Institute in Milan Italy, said in a statement. "We estimate that almost twice as many pembrolizumab responders will respond to the therapy for at least a year, 68% versus 35%."

The PD-L1 inhibitor atezolizumab (Tecentriq) received FDA approval last year for previously treated urothelial cancer. Data reported at the European Society for Medical Oncology conference last fall showed favorable results for pembrolizumab in first-line treatment of platinum-ineligible urothelial cancer for nivolumab (Opdivo) in metastatic disease that had progressed after first-line cisplatin.

Clues to Diabetes Link to Pancreatic Cancer

Half of all new pancreatic cancers occurred within a year after diagnosis of type 2 diabetes or rapid deterioration in control of existing diabetes, an analysis of 800,000 patients showed.

Linkage of pharmacy and cancer databases in two countries showed that 25% of new pancreatic cancers in Belgium and 18% of those in the Lombardy region of Italy were diagnosed within 90 days after patients started treatment for type 2 diabetes. Patients with pancreatic cancer also switched significantly more quickly from oral antidiabetic therapy to incretin-based therapy or insulin -- a sign of more aggressive diabetes and loss of disease control -- as compared with diabetic patients who did not develop pancreatic cancer.

The results suggested that using prescription databases, perhaps in combination with biomarkers for pancreatic cancer, could lead to earlier diagnosis of pancreatic cancer, which has one of the worst prognoses among cancers, in part because of late diagnosis.

"There is currently no good, noninvasive method for detecting pancreatic cancer that is not yet showing any visible signs or symptoms," , of the International Prevention Research Institute in Lyon, France, said in a statement. "We hope that our results will encourage the search for blood markers indicating the presence of pancreatic cancer, which could guide decisions to perform a confirmation examination, like endoscopy."

Clinicians and patients should be aware that a diagnosis of type 2 diabetes or rapid deterioration of diabetes control with medication could be an early sign of pancreatic cancer, she added.

The analysis included 368,377 diabetic patients in Belgium during 2008 to 2013 and 456,311 diabetic patients in Lombardy during 2008 to 2012. More than 2,600 pancreatic cancers were diagnosed during the same period in the two areas. About half of the pancreatic cancers were diagnosed within 12 months after a patient started treatment for type 2 diabetes.

An early switch to incretin or insulin therapy had a particularly strong association with pancreatic cancer, reaching a hazard ratio of 3.5 in the Belgian patients when the switch from oral therapy occurred within 90 days.

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    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined 51˶ in 2007.

Primary Source

European Cancer Congress

Lagendijk M, et al "Breast conserving therapy and mastectomy revisited: Breast cancer-specific survival and the influence of prognostic factors in 129,692 patients" ECCO 2017; Abstract 1106.

Secondary Source

European Cancer Congress

Necchi A, et al Pembrolizumab vs investigator choice chemotherapy for previously treated advanced urothelial cancer: Phase III KEYNOTE-045 study" ECCO 2017; Abstract 1154.

Additional Source

European Cancer Congress

Autier P, et al "Early detection of pancreatic cancer among diabetic patients: results from prescription database analyses" ECCO 2017; Abstract 0410.