Stuart M. Lichtman, MD, FACP

Breast cancer is predominantly a disease of older women. Many of these older patients with breast cancer have low-risk disease owing to low proliferation indices, positive hormone receptors, node-negativity, or p53-negative and HER-2 (human epidermal growth factor 2)-negative tumors.[1,2] They do well without chemotherapy and will receive adjuvant hormonal therapy with tamoxifen or an aromatase inhibitor. Yet there are older women who do not have these favorable tumor characteristics and so are potential candidates for chemotherapy. The review by Muss points out this issue, highlighting benefits of chemotherapy and describing appropriate treatment regimens for these patients.

The review by Balducci provides an excellent overview of issues regarding the pharmacotherapy of anticancer therapy in older patients. The introduction to geriatrics emphasizes the need to be able to determine the patient’s physiologic age.

The issue of cancer in the elderly is of growing concern given the aging population. It is a particular issue in lung cancer, where the median age of patients is over 60.

Approximately 212,920 new cases of invasive breast cancer were estimated to occur in the United States in 2006.1 The incidence rate has continued to rise slowly over the past 20 years due to the continued increase of breast cancer in women aged 50 and older (375 cases per 100,000 women), peaking at 75 to 79 years of age (525 per 100,000 women).

There has been an epidemiologic shift occurring with the aging of our society. It has long been recognized that the most significant risk factor for the development of cancer is aging. This, together with the epidemiologic shift, has resulted in a marked increase in the number of older patients with cancer.

The risk of cancer increases with age, and as the US population rapidly ages, the number of older adults seeking treatment for cancer is also increasing dramatically. However, this growing population of older adults has been underrepresented in clinical trials that set the standards for oncology care. In addition, most clinical trials conducted to date have not addressed the problems that accompany aging, including reduced physiologic reserve, changes in drug pharmacokinetics, and the impact of comorbid medical conditions and polypharmacy on treatment tolerance. As a result, there are variations in treatment patterns between older and younger adults and few evidence-based guidelines accounting for the changes in physiology or pharmacokinetics that occur with aging. This article examines the demographics of cancer and aging, the barriers to enrollment of older adults on clinical trials, and approaches for future trials to address the needs of the older patient.

An increasing body of evidence suggests that geriatric patients can benefit from and tolerate standard chemotherapy similarly to younger patients in the settings of both early- and advanced-stage colorectal cancer. Assessment of this unique population requires more comprehensive evaluation in addition to routine history, physical examination, and laboratory tests. Specific considerations of their physiologic functional changes will help physicians better manage these patients. Ongoing studies are now designed to better understand the decision-making process, safety profile, and efficacy of various treatment regimens in geriatric patients.

Many elderly individuals have substantial life expectancy, even inthe setting of significant illness. There is evidence to indicate that elderlyindividuals derive as much survival benefit as younger patientsfrom standard chemotherapy approaches in advanced colorectal cancer.Effective treatments should not be withheld from older patients onthe basis of age alone. Treatment decisions should be based on functionalstatus, presence of comorbidities, and consideration of drug-specifictoxicities that can be exacerbated in older individuals due to decreasedfunctional reserve. Infusional and weekly fluorouracil (5-FU)regimens are better tolerated than bolus and monthly regimens. Oralcapecitabine (Xeloda) reduces the frequency of a number of toxicitiescompared with bolus 5-FU, including stomatitis, a particularly debilitatingtoxicity in many elderly patients. The effectiveness and tolerabilityof oxaliplatin and irinotecan (Camptosar) appear to be similar inolder and younger patients. Older patients can also receive bevacizumab(Avastin), although caution is warranted in those with cardiovasculardisease. Overall survival in metastatic colorectal cancer improves withthe availability of multiple effective chemotherapeutic agents. The fullrange of effective therapies in advanced colorectal cancer should beextended to elderly patients.

The fastest growing segment of the US population is the group over the age of 65 years. In the next 30 years, this group will comprise over 20% of the population. Because 60% of all cancers occur in this age group, there will be an expected rise in the total cancer burden.