Cancer and aging: symposium of the 27th annual meeting of the Japanese society for biomedical gerontology, Tokyo

Impact of older age on clinicopathological and prognostic features of colon cancer in postmenopausal women

To clarify the clinicopathological features of colorectal cancer in older people, systematic studies considering age, sex, and the tumor locus is needed. We focused on colon cancer in postmenopausal women (<70 years, n = 68 vs. ≥70 years, n = 85), and examined the effect of age on clinicopathological features. Rates of medullary carcinoma /mucinous carcinoma were higher and pathological stages at diagnosis were less advanced in patients ≥70 years compared with <70 years. Matching pathological stages, no significant difference in disease-free interval was observed according to age; however, disease-specific survival (DSS) was poorer in patients ≥70 years than <70 years, being significantly different in stage IV cases. Regarding post-metastasis/recurrence (met/rec) cases, chemotherapy and surgery for metastasis were less frequent in those aged ≥70 years than <70 years. Post-met/rec DSS was poorer in ≥70 years, those with microsatellite instability, and those without surgery for met/rec than in each counterpart; however, post-met/rec chemotherapy exhibited no effect. Multivariate analyses revealed that an older age and no surgery for metastasis were independent predictors of disease-specific death. These findings remained after excluding stage IV cases. Older age was a potent risk factor of rapid disease-specific death after met/rec.

Mathematical modeling of solid cancer growth with angiogenesis

Background

Cancer arises when within a single cell multiple malfunctions of control systems occur, which are, broadly, the system that promote cell growth and the system that protect against erratic growth. Additional systems within the cell must be corrupted so that a cancer cell, to form a mass of any real size, produces substances that promote the growth of new blood vessels. Multiple mutations are required before a normal cell can become a cancer cell by corruption of multiple growth-promoting systems.

Methods

We develop a simple mathematical model to describe the solid cancer growth dynamics inducing angiogenesis in the absence of cancer controlling mechanisms.

Results

The initial conditions supplied to the dynamical system consist of a perturbation in form of pulse: The origin of cancer cells from normal cells of an organ of human body. Thresholds of interacting parameters were obtained from the steady states analysis. The existence of two equilibrium points determine the strong dependency of dynamical trajectories on the initial conditions. The thresholds can be used to control cancer.

Conclusions

Cancer can be settled in an organ if the following combination matches: better fitness of cancer cells, decrease in the efficiency of the repairing systems, increase in the capacity of sprouting from existing vascularization, and higher capacity of mounting up new vascularization. However, we show that cancer is rarely induced in organs (or tissues) displaying an efficient (numerically and functionally) reparative or regenerative mechanism.

Role of methylation of the hMLH1 gene promoter in the development of gastric and colorectal carcinoma in the elderly

The occurrence of malignant neoplasms increases with advancing age. Although aging and carcinogenesis are basically different processes, they share phenomena such as the accumulation of DNA damage and abnormal proteins. Recent advances in molecular biology have shown an accumulation of genetic and epigenetic changes in both aging and carcinogenesis, as well as the alteration of metabolism, immunosenescence and shortened telomeres. DNA methylation is a representative epigenetic phenomenon and is frequently involved in controlling gene functions during development and tumorigenesis. We herein focused on methylation of genes in the development of gastrointestinal carcinomas in the elderly. The proportion of gastric and colorectal carcinomas with hypermethylation of the hMLH1 promoter increases with age, reaching 25-30% of all carcinomas of the stomach and large intestine in elderly patients. These tumors have clinicopathological and molecular characteristics such as loss of hMLH1 expression, microsatellite instability, poorly differentiated histology, peritumoral inflammatory cell infiltration, low incidence of lymph node metastasis and favorable prognosis. However, methylation-related carcinogenesis accounts for up to approximately one-third of tumors, and other mechanisms; for example chromosomal instability as a result of telomere dysfunction, are responsible for the development of most carcinomas in the elderly.

[Age-related microscopic and molecular changes of the human colon, and their role in the development of colorectal cancer in elderly people]

The gastrointestinal effect of aging, the recognition of its molecular background and the mapping its connections with several diseases like sporadic colorectal cancer of elder people are a new and promising area of molecular gastroenterology. Nowadays, it is a well-known fact that some age-related molecular changes (e.g.: DNA methylation, telomere shortening) can be detected in several types of colorectal cancers. The known epidemiologic and molecular biologic features of sporadic colorectal cancer are not enough to explain the genetic, gene expression or epigenetic changes that may be involved in the increase of the disease over 45-50 age years. The connections of these alterations to the process of aging are also unclear. The understanding and custom-tailored modification of these mechanisms are of great clinical importance regarding of prevention and modern therapeutic strategies. In this review, we aimed to summarize the age-related microscopic and molecular changes of the human colon, as well as their role in the development of colorectal cancer of the elder people.

Clinicopathological features, background liver disease, and survival analysis of HCV-positive patients with hepatocellular carcinoma: differences between young and elderly patients

BACKGROUND

The aim of this retrospective study was to determine the incidence and characteristics of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) antibody-positive elderly patients with chronic hepatitis without cirrhosis.

METHODS

The study included 65 patients who developed HCC at >or=75 years of age and who received their first HCC therapy at Toranomon Hospital between 1985 and 2005. Their clinicopathological and laboratory data were analyzed and compared with those of 33 patients who developed HCC at <or=50 years of age during the same period.

RESULTS

The ratio of women patients in the elderly group (M: F = 1.1: 1) was higher than in the younger group (M: F = 5.6: 1). Also, patients in the elderly group had better liver function and prothrombin activity (P = 0.001), and lower total bilirubin (P = 0.002) than the young group. Only 11 of 65 elderly patients were diagnosed with liver cirrhosis by biopsy or peritoneoscopy before or at the time of development of HCC. Based on a discriminate score using gamma-globulin, hyaluronate level, platelet count, and sex, 27 (41.5%) elderly patients were considered to have chronic hepatitis, compared with six of 33 (18.1%) patients in the young group (P = 0.025). There were no differences in tumor number or size or tumor markers between the two groups. Survival rate was higher in the younger patients (P = 0.002), who were more likely to receive radical treatment.

CONCLUSIONS

Our results showed distinct differences in HCV-related HCC between elderly and young patients and suggested that elderly patients (especially women) could develop HCC even when liver histology shows chronic hepatitis and lack of cirrhosis.

Clinicopathological and molecular characteristics of gastric and colorectal carcinomas in the elderly

The occurrence of malignant neoplasms increases with advancing age. Although aging and carcinogenesis are basically different processes, there are phenomena common to each such as accumulation of DNA damage and abnormal proteins. Gastric and colorectal carcinomas are representative tumors in which the prevalence and the number of patients increase significantly with age. Compared with gastric and colorectal cancers occurring in younger patients, those occurring in older patients have clinicopathological differences in tumor location, gender distribution, histological type, histological diversity, multiplicity, incidence of lymph node metastasis, and prognosis. In the elderly there are peculiar types of carcinoma such as medullary-type poorly differentiated colorectal adenocarcinoma and solid-type poorly differentiated gastric adenocarcinoma, both of which occur in older women. Methylation, apoptosis, and telomere dysfunction play important roles in the development of gastric and colorectal cancers in the elderly.

[The influence of aging on pathologic and immunobiologic parameters of invasive ductal breast carcinoma]

BACKGROUND/AIM

Most human cancers, including breast one, increase in frequency with aging. The aim of this study was to explore the hypothesis that aging also alters breast cancer biology.

METHODS

The study included 120 women with primary invasive ductal carcinoma of the breast. We correlated the patients age and diagnosis with the commonly used clinical, pathological factors and newer tumor biomarkers. Immunohistochemical staining was conducted for p53, c-erbB-2, Ki-67, estrogen (ER), progesterone (PR) receptors, and angiogenesis.

RESULTS

In our study, the patients with axillary lymph node metastases and negative steroid hormone receptors (ER and PR) were significantly younger than the patients with nodal involvement and positive hormone receptors. There was also a significant association between the patients age, diagnosis and angiogenesis. No association was found between the patients age and tumour size, histological grade, p53, c-erbB-2, and Ki-67.

CONCLUSION

The results of our study supported only partially the hypothesis that the breast cancer biology is significantly affected by a patient's age.

The biological sense of cancer: a hypothesis

BACKGROUND

Most theories about cancer proposed during the last century share a common denominator: cancer is believed to be a biological nonsense for the organism in which it originates, since cancer cells are believed to be ones evading the rules that control normal cell proliferation and differentiation. In this essay, we have challenged this interpretation on the basis that, throughout the animal kingdom, cancer seems to arise only in injured organs and tissues that display lost or diminished regenerative ability.

HYPOTHESIS

According to our hypothesis, a tumor cell would be the only one able to respond to the demand to proliferate in the organ of origin. It would be surrounded by "normal" aged cells that cannot respond to that signal. According to this interpretation, cancer would have a profound biological sense: it would be the ultimate way to attempt to restore organ functions and structures that have been lost or altered by aging or noxious environmental agents. In this way, the features commonly associated with tumor cells could be reinterpreted as progressively acquired adaptations for responding to a permanent regenerative signal in the context of tissue injury. Analogously, several embryo developmental stages could be dependent on cellular damage and death, which together disrupt the field topography. However, unlike normal structures, cancer would have no physiological value, because the usually poor or non-functional nature of its cells would make their reparative task unattainable.

CONCLUSION

The hypothesis advanced in this essay might have significant practical implications. All conventional therapies against cancer attempt to kill all cancer cells. However, according to our hypothesis, the problem might not be solved even if all the tumor cells were eradicated. In effect, if the organ failure remained, new tumor cells would emerge and the tumor would reinitiate its progressive growth in response to the permanent regenerative signal of the non-restored organ. Therefore, efficient anti-cancer therapy should combine an attack against the tumor cells themselves with the correction of the organ failure, which, according to this hypothesis, is fundamental to the origin of the cancer.