The effect of age and gender on outcome after treatment for colon carcinoma

Abstract

Rationale

The aim of this study was to assess whether there are differences in treatment strategy and outcome between different age cohorts among men and women with colon cancer.

Methods

All patients with colon cancer included in the regional quality registry in Uppsala/Örebro and Stockholm between 1996 and December 2004 were analysed (n = 11 002). Patients were divided into three age categories: ≤65 years, 66–80 years and >80 years.

Results

Overall and cancer-specific survival decreased with increasing age for stages II and III colon cancer but was not influenced by gender. Older patients with stage III tumours were less likely to be referred for chemotherapeutic treatment and there was a decrease in cancer-specific survival with increasing age, from 63.7% to 51.0% to 38.4% in the three age groups. Postoperative morbidity and the number of reoperations was significantly higher in men than in women.

Conclusion

The present study shows lower cancer-specific survival among older patients than among younger patients. Gender was not a prognostic factor in cancer-specific survival.

Introduction

Colorectal cancer is a disease of the elderly. As life expectancy increases [1], so does the number of cancer patients at an older age that require treatment. Over the past 10 years there has been a steady increase in the incidence of colon cancer [2]. It is the second most common type of cancer in both men and women in Sweden, with a median age at diagnosis of 73 years in men and 76 years in women [3]. Of the 3621 new patients diagnosed with colon cancer in 2004 in Sweden, 77% were older than 65 years and 12% were over the age of 85 [4]. In everyday clinical practice there is an ongoing debate concerning what constitutes the best for patients over the age of 75–80 years. Optimal therapy is often withheld, perhaps based on assumptions and emotions of the treating physician. Elderly patients do not seem to benefit as much from improvements in therapeutic regimens as younger patients do, especially concerning tumours that require chemotherapeutic adjuvant treatment [5]. Recently Eaker et al. investigated the treatment of women of all ages with breast cancer in the Uppsala/Örebro region and reported some disturbing findings [6]. There was a definite age bias in the management of older women, with those over 70 years of age receiving less comprehensive diagnostic testing, less aggressive treatment and a later diagnosis. This resulted in a reduction of 5-year relative survival of 13% in the older age group. A recent publication by Gondos et al. [5] showed that significant increases in 5-year relative survival for the most common tumour types are more often seen among patients younger than 75 years of age than among the older patients. Elderly patients have also been shown to have inferior outcome after treatment for colorectal cancer [7], [8]. Several factors may be responsible for these differences. Patients over 75 years of age suffer more postoperative morbidity and a higher incidence of postoperative deaths [7]. This would have an impact on overall survival. It is more worrying that cancer-specific survival is lower in old patients than in younger patients with the same diagnosis [8].

In 2005 life expectancy in Sweden was 82.8 years for a woman and 78.4 years for a man [1]. Roughly 20% of the population is aged over 65 years. It is important to keep in mind that as age increases after a certain number of years, so does the relative life expectancy. Life expectancy for a 65-year-old woman is not 17.8 but 20.6 years and for a man of the same age it is 17.4 and not 13.4 years. It is thus wrong to assume that the life expectancy of an 82-year-old woman is less than 1 year; it is in fact 5 years [1]. This is often overlooked in clinical practice and an important factor to keep in mind when discussing possible benefits of different treatment modalities for the elderly.

A factor closely intertwined with increasing age is the difference in treatment outcome between men and women. In recent years, studies comparing the outcome for the two sexes have reported improved survival of women with colorectal cancer [9], [10], [11]. The present study, based on 11 002 Swedish patients with colon cancer, aimed to assess whether men and women in different age cohorts receive equal treatment and whether any potential dissimilarity has measurable consequences in outcome, regarding postoperative morbidity and mortality, cancer-specific and overall survival.