Patient approach in advanced/metastatic renal cell carcinoma: focus on the elderly population and treatment-related toxicity

Colon cancer cells cultured under hyperosmotic conditions as in vitro model to investigate dehydration effects on cancer drug susceptibility

BACKGROUND

In most clinical studies older people are underrepresented compared to the demographic reality. However, risk for some severe diseases like cancer typically increase with age. Most insight into cancer treatment comes from mixed-age patient cohorts, leading to a lack of detailed understanding of cancer drug effects in the elderly population. There is growing evidence that cancer drug effects can be influenced by dehydration conditions often found in older people. Colon cancer remains the second leading cause of death by cancer in Europe. Inter- and intra-heterogeneity of tumors contribute to why some individuals do not respond to specific cancer therapies or may often suffer a relapse.

OBJECTIVE

Our study applies an in vitro drug test system for simulating treatment with cytostatics of colorectal cancer in elderly patients with dehydration condition.

METHODS

Two well-known colon cancer cell lines, Caco-2 and RKO, harboring defined cancer-related mutations, were step-wisely adapted from routine culture medium to a severe hyperosmotic condition (397 mOmol/kg) by adding sodium chloride to the medium. We investigated the effects of these cell culture conditions, which should mimic cellular dehydration in elderly people, on the growth characteristics of the cells. Therefore, cell proliferation was investigated by measuring population doubling times. Furthermore, we investigated how the metabolic activity of the cells was influenced by treatment with different concentrations of cyclophosphamide (CPA) under normal and hyperosmotic conditions.

RESULTS

We found that Caco-2 and RKO cell lines have an identical cell doubling time of 23 hours in normosmotic medium. However, hyperosmotic medium lifted the doubling time of Caco-2 cells to 31 hours while that of RKO cells did not change. Despite reduced cell proliferation rates, hyperosmotic medium sensitized Caco-2 cells to treatment with 10 mM CPA for 48 hours as measured by metabolic activity assays on ATP levels.

CONCLUSIONS

The two investigated colon cancer cells lines reacted differently to hyperosmotic conditions. Only the growth of Caco-2 cells was reduced by increased osmolality. Despite this reduced growth their sensitivity to an alkylating cytostatic agent was even slightly increased. We are now in line to examine these effects in more detail and with more tumor cell lines.

Toxicity of Cancer Therapies in Older Patients

PURPOSE OF THE REVIEW

In clinical practice, older patients are often undertreated due to underrepresentation in clinical trials and fear of toxicity. Our objective was therefore to review toxicities that are specific to older cancer patients, to review risk factors in order to help physicians guide their decisions, and to review interventions that can be implemented in routine clinical practice to prevent toxicity induced by cancer therapies.

RECENT FINDINGS

On the whole, reviews report similar number and frequency as well as similar grade 3 or 4 adverse events between subjects older and younger than 65 years. Yet patients included in clinical trials are often not representative of real-life patients and are often fit older cancer patients. Moreover, tolerance to the additive impact of multiple adverse effects is different between older and younger patients. And specific symptoms such as stomatitis may cause a series of consequences such as dehydration, denutrition, renal insufficiency, and adverse events of renally excreted drugs. Older patients are at high risk of toxicity due to many factors but mainly due to the prevalence of frailty in this population that has been estimated to be around 40% increasing the risk of chemotherapy intolerance. As a consequence, interventions must be implemented according to altered domains of comprehensive geriatric assessment in order to improve anticancer tolerance. These interventions are reviewed here.

Elderly patients with metastatic renal cell carcinoma: position paper from the International Society of Geriatric Oncology

Therapy for metastatic renal cell carcinoma should be tailored to the circumstances and preferences of the individual patient. Age should not be a barrier to effective treatment. Systematic geriatric screening and assessment contributes to the goal of personalised management, in addition to the involvement of a multidisciplinary team. A task force from the International Society of Geriatric Oncology (SIOG) updated its 2009 consensus statement on the management of elderly patients with metastatic renal cell carcinoma by reviewing data from studies involving recently approved targeted drugs and immunotherapies for this disease. Overall, it seems that age alone does not appreciably affect efficacy. Among the pivotal studies that were included, there is a striking scarcity of analyses that relate toxic effects to patient age. Even if the adverse effects of therapy are no more frequent or severe in elderly patients than in their younger counterparts, the practical, psychological, and functional impact of treatment may be greater, especially if toxic effects are chronic and cumulative.

Cytotoxic effects of chemotherapy on cancer and immune cells: how can it be modulated to generate novel therapeutic strategies?

The first objective to use chemotherapy is to kill cancer cells. However, it is common knowledge that these drugs can also damage healthy host cells, especially immune cells, and thus impair the endogenous antitumor response. Here, we focus on the cytotoxic effects of chemotherapy on tumor cells and immune cells. It is not enough to simply kill cancer cells, and causing immunogenic cell death will impair the adaptive immune system's ability to fight the remaining cancer cells. On the other hand, the killing of immune cells can also enhance tumor growth. A study of the repercussions of the cytotoxic effects of chemotherapy is of great importance to evaluate the antitumor response. Strategies can be proposed to promote the 'good way' for cancer cells to die and to avoid the adverse side effects of chemotherapy on immune cells in order to strengthen the role of the immune system in the antitumor response.