Purpose To update the ASCO clinical practice guideline on adjuvant endocrine therapy on the basis of emerging data on the optimal duration of treatment, particularly adjuvant tamoxifen. Methods ASCO convened the Update Committee and conducted a systematic review of randomized clinical trials from January 2009 to June 2013 and analyzed three historical trials. Guideline recommendations were based on the Update Committee's review of the evidence. Outcomes of interest included survival, disease recurrence, and adverse events. Results This guideline update reflects emerging data on duration of tamoxifen treatment. There have been five studies of tamoxifen treatment beyond 5 years of therapy. The two largest studies with longest reported follow-up show a breast cancer survival advantage with 10-year durations of tamoxifen use. In addition to modest gains in survival, extended therapy with tamoxifen for 10 years compared with 5 years was associated with lower risks of breast cancer recurrence and contralateral breast cancer. Recommendations Previous ASCO guidelines recommended treatment of women who have hormone receptor–positive breast cancer and are premenopausal with 5 years of tamoxifen, and those who are postmenopausal a minimum of 5 years of adjuvant therapy with an aromatase inhibitor or tamoxifen followed by an aromatase inhibitor (in sequence). If women are pre- or perimenopausal and have received 5 years of adjuvant tamoxifen, they should be offered 10 years total duration of tamoxifen. If women are postmenopausal and have received 5 years of adjuvant tamoxifen, they should be offered the choice of continuing tamoxifen or switching to an aromatase inhibitor for 10 years total adjuvant endocrine therapy.

The Update Committee recommends that postmenopausal women with hormone receptor-positive breast cancer consider incorporating AI therapy at some point during adjuvant treatment, either as up-front therapy or as sequential treatment after tamoxifen. The optimal timing and duration of endocrine treatment remain unresolved. The Update Committee supports careful consideration of adverse effect profiles and patient preferences in deciding whether and when to incorporate AI therapy.

Purpose To update the ASCO clinical practice guideline on adjuvant endocrine therapy based on emerging data about the optimal duration of aromatase inhibitor (AI) treatment. Methods ASCO conducted a systematic review of randomized clinical trials from 2012 to 2018. Guideline recommendations were based on the Panel’s review of the evidence from six trials. Results The six included studies of AI treatment beyond 5 years of therapy demonstrated that extension of AI treatment was not associated with an overall survival advantage but was significantly associated with lower risks of breast cancer recurrence and contralateral breast cancer compared with placebo. Bone-related toxic effects were more common with extended AI treatment. Recommendations The Panel recommends that women with node-positive breast cancer receive extended therapy, including an AI, for up to a total of 10 years of adjuvant endocrine treatment. Many women with node-negative breast cancer should consider extended therapy for up to a total of 10 years of adjuvant endocrine treatment based on considerations of recurrence risk using established prognostic factors. The Panel noted that the benefits in absolute risk of reduction were modest and that, for lower-risk node-negative or limited node-positive cancers, an individualized approach to treatment duration that is based on considerations of risk reduction and tolerability was appropriate. A substantial portion of the benefit for extended adjuvant AI therapy was derived from prevention of second breast cancers. Shared decision making between clinicians and patients is appropriate for decisions about extended adjuvant endocrine treatment, including discussions about the absolute benefits in the reduction of breast cancer recurrence, the prevention of second breast cancers, and the impact of adverse effects of treatment. Additional information can be found at www.asco.org/breast-cancer-guidelines .

Purpose The current epidemic of prescription opioid misuse has increased scrutiny of postoperative opioid prescribing. Some 6% to 8% of opioid-naïve patients undergoing noncancer procedures develop new persistent opioid use; however, it is unknown if a similar risk applies to patients with cancer. We sought to define the risk of new persistent opioid use after curative-intent surgery, identify risk factors, and describe changes in daily opioid dose over time after surgery. Methods Using a national data set of insurance claims, we identified patients with cancer undergoing curative-intent surgery from 2010 to 2014. We included melanoma, breast, colorectal, lung, esophageal, and hepato-pancreato-biliary/gastric cancer. Primary outcomes were new persistent opioid use (opioid-naïve patients who continued filling opioid prescriptions 90 to 180 days after surgery) and daily opioid dose (evaluated monthly during the year after surgery). Logistic regression was used to identify risk factors for new persistent opioid use. Results A total of 68,463 eligible patients underwent curative-intent surgery and filled opioid prescriptions. Among opioid-naïve patients, the risk of new persistent opioid use was 10.4% (95% CI, 10.1% to 10.7%). One year after surgery, these patients continued filling prescriptions with daily doses similar to chronic opioid users ( P = .05), equivalent to six tablets per day of 5-mg hydrocodone. Those receiving adjuvant chemotherapy had modestly higher doses ( P = .002), but patients with no chemotherapy still had doses equivalent to five tablets per day of 5-mg hydrocodone. Across different procedures, the covariate-adjusted risk of new persistent opioid use in patients receiving adjuvant chemotherapy was 15% to 21%, compared with 7% to 11% for those with no chemotherapy. Conclusion New persistent opioid use is a common iatrogenic complication in patients with cancer undergoing curative-intent surgery. This problem requires changes to prescribing guidelines and patient counseling during the surveillance and survivorship phases of care.

PurposeTo provide recommendations for appropriate cytotoxic chemotherapy dosing for obese adult patients with cancer.MethodsThe American Society of Clinical Oncology convened a Panel of experts in medical and gynecologic oncology, clinical pharmacology, pharmacokinetics and pharmacogenetics, and biostatistics and a patient representative. MEDLINE searches identified studies published in English between 1996 and 2010, and a systematic review of the literature was conducted. A majority of studies involved breast, ovarian, colon, and lung cancers. This guideline does not address dosing for novel targeted agents.ResultsPractice pattern studies demonstrate that up to 40% of obese patients receive limited chemotherapy doses that are not based on actual body weight. Concerns about toxicity or overdosing in obese patients with cancer, based on the use of actual body weight, are unfounded.RecommendationsThe Panel recommends that full weight–based cytotoxic chemotherapy doses be used to treat obese patients with cancer, particularly when the goal of treatment is cure. There is no evidence that short- or long-term toxicity is increased among obese patients receiving full weight–based doses. Most data indicate that myelosuppression is the same or less pronounced among the obese than the non-obese who are administered full weight–based doses. Clinicians should respond to all treatment-related toxicities in obese patients in the same ways they do for non-obese patients. The use of fixed-dose chemotherapy is rarely justified, but the Panel does recommend fixed dosing for a few select agents. The Panel recommends further research into the role of pharmacokinetics and pharmacogenetics to guide appropriate dosing of obese patients with cancer.