The influence of advanced age on cancer occurrence and growth

Immunosenescence: limitations of natural killer cell-based cancer immunotherapy

Cancer is primarily considered a disease of old age. Immunosenescence refers to the age-associated changes in the immune system, and its contribution to the increased risk of cancer in old individuals has been discussed for many years. Natural killer (NK) cells are cytotoxic innate immune cells specialized in defence against tumour and virus-infected cells. NK cell cytotoxicity is the result of a fine balance between activating and inhibitory receptors. Several activating receptors have been identified that recognize different ligands frequently found over-expressed on tumour cells or virus-infected cells. The most important NK cell inhibitory receptors interact with major histocompatibility complex class I molecules expressed on almost all nucleated cells preventing NK cell-mediated lysis of healthy cells. NK cell immunosenescence is characterized by a redistribution of NK cell subsets, a diminished expression of several activating receptors and lower per-cell cytotoxicity. Altered expression of activating receptors has also been described in young and elderly cancer patients probably due to chronic exposure to ligands on tumour cells. Thus, the effect of both age and cancer may act synergistically to diminish NK cell-mediated tumour immunosurveillance. Different strategies harnessing the power of NK cells to target tumour cells have been designed including adoptive therapy with autologous or allogeneic expanded NK cells. In addition, checkpoint blockade of inhibitory receptors and the use of agonist antibodies to stimulate activating receptors are emerging areas of research. In this context, the effect of immunosenescence should be considered to improve the efficiency of cancer immunotherapy.

Treating elderly patients with hormone sensitive breast cancer: what do the data show?

Elderly patients with breast cancer frequently present with one or more comorbid conditions in addition to their cancer, and this can complicate clinicians' treatment decisions. Declining estrogen levels increase the risk for conditions such as cardiovascular disease and osteoporosis in the elderly. Evidence from clinical trials suggests that the elderly are frequently underrepresented; this may be due to an inherent reluctance among physicians to prescribe the latest, most effective therapies and/or recommend elderly patients for participation in clinical trials. Nonetheless, there is evidence that breast cancer in the elderly is generally more indolent than in younger patients, with a low proliferative and invasive capacity and a high degree of hormone responsiveness, making elderly patients ideal candidates for adjuvant endocrine therapies. The aromatase inhibitors, including anastrozole, letrozole, and exemestane, have proven to be well tolerated and superior alternatives to tamoxifen for post-menopausal women with hormone-sensitive breast cancer, whether used upfront or sequentially with adjuvant tamoxifen. Although the elderly have also been underrepresented in clinical trials of the aromatase inhibitors, evidence from the major trials has not shown any decrement in efficacy or major safety concerns when these drugs are used in older populations. While recently published data from MA.17 and the Breast International Group 1-98 showed letrozole to be effective irrespective of age, clinicians should carefully consider underlying comorbidities when prescribing adjuvant endocrine treatments to elderly patients with breast cancer.

Cancer in older men: a gender-based review

Cancer is a common condition of the older male. Risk factors for developing a malignancy include genetic, environmental and life style features. Cancer epidemiology and prognosis differ depending on the age and gender of the population being studied. In the group of men older than 65 years, the most common malignant tumors are prostate, lung, colon and pancreatic cancer. Treatment options vary depending on the stage of the tumor when it is diagnosed, and the decision for therapeutic versus palliative interventions will depend upon the functional status, comorbidity and personal wishes of the patients.