Colorectal cancer surgery remains effective with rising patient age

Multiple treatment options for patients with colorectal cancer exist. Patient age alone does not provide relevant information, rather comprehensive physical assessment is crucial. Biologically younger patients of the same chronological age as prematurely aged patients may require different treatment approaches [1]. The decision whether a patient will profit most from radical surgery or from non-oncological limited procedures in terms of expectancy and quality of life should be made on an individual basis in a multidisciplinary tumor conference. If correctly assessed and treated, the majority of patients older than 80 years maintain social independence after surgery [15]. Although it is difficult to predict the individual outcome of aged multimorbid patients [10], this study shows that oncological long-term results do not differ between age groups.

Here, young versus elderly patients, who all underwent oncological resection for colorectal cancer, were compared. The aim was to reveal relevant differences for elderly patients, who tend to have higher comorbidities. By the retrospective setting, the study presents relevant findings which may not be obtained by prospective trials with strict inclusion criteria regarding comorbidity or age. Only patients undergoing curative or palliative resection of their primary tumor were included in this study. Thus, multimorbid patients who did not undergo surgery were missed. However, inclusion of solely surgical patients allowed the comprehensive analysis of histopathological data, like TNM status and tumor grading.

In a review including 34,194 patients from 28 original studies, characteristics of young versus old patients with colorectal cancer with and without tumor resection were analyzed [10]. Preexisting comorbidities were more frequent in the elderly, but it was methodically impossible to perform a meta-analysis due to different definitions and morbidity assessments. Furthermore, complications upon treatment were significantly higher in elderly patients, mainly including respiratory, cardiovascular, cerebrovascular, or thromboembolic morbidity [10]. As found in our study, higher rates of comorbidities and higher ASA scores required a longer hospital stay for elderly patients for the preoperative assessment and postoperative surveillance, as well as longer postsurgical intensive care monitoring. However, an increased number of general complications in elderly patients may also have led to a prolonged hospital and ICU stay [3, 10].

Whether increasing patient age is associated with limited or more advanced tumor stages has been discussed controversially [4, 10, 13]. Some authors describe higher tumor stages for young patients [13], as found in our study. Possible explanations are increased symptom tolerance and less aggressive screening or surveillance among younger people, leading to higher stages at diagnosis. Other authors propagate higher tumor stages for elderly patients, maybe due to masked signs of malignancies and altered presentation of signs and symptoms of cancer in the elderly [4, 10]. Tumor genetics could explain interobserver and interindividual differences [5, 16]. Colorectal cancers of the sporadic microsatellite instability pathway are often associated with advanced patient age, proximal tumor localization, early tumor stages, mucinous or signet ring cell subtype, and poor differentiation but favorable prognosis [13, 17, 18]. This may lead to the reduced rate of synchronous metastasis and the higher rate of right sided tumors that has been identified in the elderly patients of our cohort. Shortening of telomeric length and metabolic changes during cell senescence may play a further not yet identified role [5]. However, neither in this nor in a previous study [18], we identified a correlation of the histological tumor subtype and patient age.

Concordant to our results, the median absolute frequency of postoperative mortality in the studies included in the review mentioned before [10] was 3 % in the less than 65 years age group, 6 % for 65–74 years, 9 % for 75–84 years, and 19 % in the 85 years and above age group. Contradictory to our results, the proportion of patients undergoing emergency surgery was described more than twice as high in the 85 years and above group than in the less than 65 years group [10]. Survival of emergency cases has been shown to be poorer than in those who undergo elective surgery as a result of a higher perioperative mortality rate after emergency surgery (p < 0.001 for our cohort, data not shown) [3, 10, 13]. Differences between studies may be explained, at least in part, by the considerably lower number of patients in our analysis.

In concordance with the literature [10], we did not find a significant difference for anastomotic leakage between young and elderly patients. The finding that curative resections decrease with advancing age was not confirmed in our study, however, could be attributed to age-related differences in seeking medical advice, recognition of symptoms, or primary-care referral patterns [10]. In a prospective study of 57 patients aged 80 years or older and undergoing resection of their primary colorectal carcinoma, Kruschewski et al. [3] showed proof that oncological resections should not be denied to older patients. Based on the fact that age-corrected survival of elderly and younger patients is comparable, and in concordance with our study, lethality in elderly patients was identified to be mainly caused by general complications. None of the 57 patients described by Kruschewski et al. [3] died because of surgical morbidity. Thus, limited resections for fear of an otherwise elevated risk of anastomotic leakage cannot be justified [3]. Similarly, O'Connor et al. [12] found that 28 patients aged 40 years and younger had no differences of survival compared to 190 patients aged over 40 years, although younger patients had higher rates of mucinous adenocarcinoma. In contrast, Chou et al. [13] described poorer disease-free survival for elderly patients. However, the latter study raises some questions as older patients with obviously higher chance of dying due to any reason had reduced disease free survival, but not overall survival. The broad literature does not confirm relevant differences of cancer-specific survival between older and younger patients who underwent curative surgery [3, 10]. In a review, which is in line with our data, 2-year tumor-specific survival rates for patients <65, 65–74, 75–85, and ≥85 years were 89 %, 85 %, 85 %, and 78 %, respectively [10].