Despite the improvements in the early detection of gastric cancer (GC), it remains one of the leading causes of cancer-related mortality worldwide (1, 2). Surgical resection is generally recommended as standard treatment for curable GC. Furthermore, systemic chemotherapy is widely accepted as palliative treatment for patients with unresectable, advanced or recurrent GC and was shown to improve the quality of life and prolong survival time. Previous studies have indicated the superiority of systemic chemotherapy compared to best supportive care (BSC) in patients with advanced or recurrent GC (3–5) and several phase III trials investigating systemic chemotherapy in advanced GC patients have been conducted (6–11). Recently, several clinical trials assessed the tolerability or efficacy of systemic chemotherapy, including adjuvant chemotherapy, in geriatric patients with advanced or recurrent GC and demonstrated its feasibility (12–17). However, the effect of systemic chemotherapy in the prognosis of geriatric patients with advanced or recurrent GC remains unclear. In addition, standardized regimens have not been validated. It may be difficult to standardize cancer treatments for geriatric patients, as the ability to tolerate intensive chemotherapy is largely dependent on the patient's physical background.

In the present study, we investigated clinicopathological characteristics, including the presence of concomitant illnesses, such as cardiorespiratory disease, in geriatric patents with advanced or recurrent GC and evaluated the prognostic significance of intensive chemotherapy. The results of our study may affect decision making regarding treatment for geriatric patients with advanced or recurrent GC.

The overall elderly population is currently increasing, in Japan as well as other Asian and Western countries (1, 2). As a result, the number of geriatric patients with malignant neoplasms is also increasing. Therefore, there is a need for the development and establishment of a therapeutic strategy for malignant neoplasms in geriatric patients. However, the decision to administer chemotherapy to geriatric patients with malignant neoplasms may be difficult, as the therapeutic strategy applied to this population is identical to that for younger patients. The difficulty in standardizing therapeutic regimens may be due to the fact that the therapeutic strategies for geriatric cancer patients depend on their physical and/or social background. Numerous retrospective and prospective cohort studies regarding the therapeutic indications for geriatric GC patients are currently performed in Japan; however, the criteria for selecting surgery or chemotherapy for such patients remain unclear. It is important to consider clinical characteristics, such as underlying or concomitant illness, when deciding on the therapeutic strategy, particularly in geriatric patients. Therefore, we focused on concomitant illness in geriatric patients with GC and evaluated its effect on chemotherapeutic indications.

A significant survival benefit for first- and second-line chemotherapy compared to BSC in advanced or recurrent GC was previously reported (19, 20). Therefore, a shift from first- to second-line chemotherapy may exert a significant effect on survival benefit. By contrast, although the precise indications for the administration of first- or second-line chemotherapy for geriatric GC remains unclear, the non-administration of second-line chemotherapy was significantly correlated with the presence of cardiorespiratory disease in the present study (data not shown).

As regards the survival analysis, the presence of cardiorespiratory disease was not identified as an independent factor for poor prognosis. However, the administration of chemotherapy was an independent factor for better prognosis, suggesting that chemotherapy safely administered to geriatric GC patients, even those with cardiorespiratory disease, may contribute to a better prognosis. Moreover, these findings suggested that the use of chemotherapy for geriatric GC may be of prognostic significance regardless of concomitant illness. However, chemotherapy may exert a beneficial effect on geriatric patients without critical concomitant illness; thus, the chemotherapeutic regimen should be adapted for such patients. Therefore, an accurate assessment of the physical ability of geriatric patients with GC is required to ensure adequate and safe treatment.

The Comprehensive Geriatric Assessment (CGA) is a multidimensional tool used to evaluate comorbidities, nutrition, cognition, functional status and geriatric syndromes. CGA is also used to identify patients at increased risk of adverse outcomes and guide management (21). In previous studies, the CGA tool and the frailty index for geriatric cancer patients were shown to provide valuable information through the prediction of complications from chemotherapy and tolerance to treatment (22, 23).

In the present study, we demonstrated a survival benefit in geriatric patients with advanced or recurrent gastric cancer receiving chemotherapy. We also demonstrated that chemotherapy was safer and better tolerated in geriatric GC patients without cardiorespiratory diseases. Moreover, geriatric patients with malignancies commonly exhibit variations in physical status, cognitive function and social environment. Thus, assessments of the general condition of geriatric gastric cancer patients, including various physical, cognitive and social factors, using methods such as CGA or other modified assessment tools, must be established as a standard clinical routine. These issues are currently under evaluation. The clinical application of such criteria may aid in the decision to administer intensive chemotherapy to geriatric patients with advanced or recurrent gastric cancer. Further studies are required to investigate the reproducibility of the present results in a larger cohort study or prospective trials and to establish acceptable criteria for cancer therapy in geriatric gastric cancer patients.