1 Introduction

Colorectal cancer (CRC) is the second most common cancer in men and women in developed countries, in many cases arising from benign lesions due to genetic or non-genetic imbalance [1,2]. More than 70% of CRC are found in patients aged 65 years or older and the number of older CRC patients is expected to greatly increase over the coming decades [3].

Approximately one-third of CRC patients present as an emergency [4] and despite advances in surgical technology and postoperative treatment, emergency CRC resection remains a high-risk procedure, especially in elderly patients with morbidity and mortality rates of 11-35% and 9-22%, respectively.

Age, comorbidities, American Society of Anesthesiologists (ASA) score, among other factors, have been reported as significant risk factors. However, age alone predicts poor tolerance of cancer treatment and the heterogeneity of the older cancer population requires a tailored approach that considers individual frailty, especially in the emergency setting [5].

In the present study, we aimed to compare the clinical findings and perioperative outcomes after emergency surgery for CRC in the elderly population with those observed in younger patients.

2 Patients and methods

We retrieved data from the Operating Room Registry of the Department of Surgery of San Donato Hospital in Arezzo and from the Acute Care Surgery Registry of the University Hospital Sant’Andrea of Rome[6]. For the purpose of this study, patients undergoing emergency surgery for colorectal cancer from June 2012 to June 2017 were analyzed. Colorectal procedures were selected on the basis of the International Classification of Diseases (ICD-9-CM) [codes 45.4x, 45.52, 45.7x, 45.8, 46.94, 48.62, 48.63]. Emergency resections were defined on the basis of the National Confidential Enquiry into Patient Outcome and Death classification (NCEPOD) [7]. In an attempt to avoid bias in the research, only the patients treated in a dedicated operating room within 48 hours of admission were considered eligible for this study. The above time limit was determined following the suggestion of the Timing of Acute Care Surgery classification proposed by the World Society of Emergency Surgery [8]. Patients were initially split into two main groups, named elderly and non-elderly group. The elderly group was comprised of patients of 65 years of age or above, while the non-elderly group was comprised of patients under 65 years. The elderly group patients were in turn divided into three subgroups based on age as follows: Subgroup A: 65-74ys, Subgroup B: 75-84ys and Subgroup C: >85ys. All patient records were reviewed, including demographics (sex and age at surgery), clinical data (ASA score, BMI), onset of symptoms, comorbidities, surgical procedures, tumor location and pathological features. Onset symptoms were defined as follows: obstruction, acute abdominal symptoms (encompassing peritonitis, abscess and/or overt perforation), and bleeding. All patients were histopathologically diagnosed with primary adenocarcinoma. Tumour site was defined as right or left using the middle colic artery as landmark. Tumors located below the peritoneal reflection were excluded. Pathological data included the T and N stage of colorectal cancer, grading, the lymph node harvest (LNH) and the lymph node ratio (LRN) according to well described criteria [9]. A formal Institutional Review Board approval was not required because of the non-interventional retrospective design; however, a consent for the collection of data for scientific purpose was obtained from all patients at hospital admission.

3 Discussion

The elderly population is steeply increasing worldwide and it presents notable challenges when planning and delivering healthcare services. There is no agreement on a definition of elderly. In the literature the cut-off for a definition of elderly varies from being either 65 or 75 years of age. Many studies define as “elderly” only patients older than 80 years [10, 11, 12, 13, 14, 15]. At present, the WHO still consider as elderly those individuals of 60 years or over; however most scientific societies define patients as elderly if their age is 65 year or more. After a literature review, we have chosen 65 years as an initial cut-off to define patients as elderly according to the decision by other Italian scientific societies (16, 17).

Elderly patients have an increased operative risk and high postoperative morbidity and mortality rate because of associated diseases such as hepatic, cardiovascular, and pulmonary diseases [18, 19, 20, 21, 22]. These patients are often also called “frail”. Frailty is defined as a condition of vulnerability strictly associated with an increased risk of poor outcomes [23, 24, 25]. In the literature, the “frailty phenotype” is a condition defined by the presence of five criteria. These are: unintentional weight loss, self-reported exhaustion, weakness (grip strength), slow walking speed and low physical activity.

A lot of pathogenic mechanisms could be proposed to explain frail phenotype onset. One of most promising is the elevation of ROS (Reactive oxygen species) and oxidative stress [26,27]. These factors are increased in several age-related diseases [28, 29, 30]

In the emergency setting, the frailty of the elderly becomes more critical and any emergency surgery has to be considered a very high risk procedure because it may suddenly put out of balance an otherwise normal subject.

Therefore, when assessing risk factors for surgery, it would be better to consider biological age rather than chronological age [29]. Many studies have demonstrated that age alone is not a prognostic factor in short-term outcomes and survival after colonic surgery [31, 32, 33]. On the contrary, important factors affecting morbidity and mortality rates are emergency surgery and comorbidities. Smothers et al. stated that emergency surgery adversely affects immediate surgical morbidity and mortality, without distinguishing patients by age [34].

The significantly higher number of comorbidities is the most important predictive factor of postoperative complications or early mortality. In agreement with literature and as expected, in this study elderly patients present more comorbidities than younger ones and they were classified as ASA III. In our experience, individual preoperative risk was assessed using ASA score because it can be quickly determined at admission and it is predictive of morbidity and mortality [21, 35]. Not unlike with other studies, the most frequent onset symptom was obstruction in both study groups. This symptom was generally associated with left sided tumours. In our experience, left sided tumours were slightly more frequent in elderly patients, but we did not find any significant differences in terms of tumour location between the two groups.

Emergency surgical treatment of colorectal cancer depends on tumour site, intraoperative findings, patient’s general condition and surgeon experience [36, 37]. With regards to approach, according to previous reports, our series shows a significantly lower number of laparoscopic approachs in elderly patients than in younger ones. Typically, patients with right-sided lesions underwent right hemicolectomy with primary anastomosis. In cases of left-sided tumours, the optimal surgical treatment is still a matter of debate and mainly includes colorectal resection and primary anastomosis, resection and anastomosis with temporary diverting ileostomy and Hartmann’s procedure. The latter one was previously considered a first-choice procedure in emergency colon surgery since it is fast to perform and prevents anastomotic leakage, but it requires a second stage to reverse the colostomy [38]. Therefore, there has been reported a shift regarding the surgical approach with a higher rate of one-stage procedure being performed [6,39, 40, 41]. Many studies, however, still report an increasing number of surgical procedures involving the creation of a diverting stoma in elderly patients [42]. Formisano et al. suggest that primary resection and anastomosis is optimal in selected patients with low risk; temporary ileostomy is indicated in patients with intermediate risk, advanced obstruction, perforation or locally advanced condition; Hartmann’s procedures should be preferred as the safer surgical procedure when doubt exists [43]. In our series no differences were found in the number of right hemicolectomy and left colorectal resections and primary anastomosis performed between the two groups. In the face of left-sided tumour and consistent risk of anastomotic leakage, Hartmann’s procedure was the preferred procedure in elderly patients while primary resection and anastomosis with diverting temporary ileostomy was the more common treatment of choice in the non-elderly group.

Colorectal tumours submitted to emergency surgery are at a more advanced stage and this finding is related to an increase in perioperative mortality rate and poor survival [44, 45]. Similarly, we report a high rate of T3 and T4 tumour stages in both groups. No statistically significant differences in N stage were observed in our study; however we reported a higher number of N+ stage, mainly N2, in the non-elderly group.

A minimum examination of 12 harvested lymph nodes is recommended to achieve correct staging [46, 47, 48]. Many studies showed that emergency surgery does not influence the adequacy of lymph node harvest [49, 50, 51], while age is a statistically significant variable affecting LNH [52, 53]. Our study shows a similar decreasing rate of adequate lymph node harvest in elderly patients; however no difference was found regarding LNR. We documented that a palliative, or better defined, non-adequate resection has been frequently performed in the elderly group, especially in the very elderly patients. We can not clearly explain this finding. Knowing that all the staff surgeons involved have colorectal surgical expertise and follow the same oncologic principles, we postulate that some surgeons’ choices could be guided by making intraoperative risk-benefit analysis leading to a less extensive procedure in the elderly patients such as the minimum bowel length resection required to reach the abdominal wall while performing Hartmann’s operation.

4 Conclusions

Emergency presentation of colorectal cancer is common and emergency surgery represents a high risk procedure, especially in elderly patients. The non-elderly group presented at more advanced tumor stages, but even so, they more often underwent curative resections, compared to the elderly group. Age alone should not be considered to be more of a contraindication or a worse predictor than other factors for the outcome after colorectal surgery on elderly patients. A personalized strategy is required, considering each patient’s comorbidities, performance status, and life style. Despite the recent changes in surgical approach, Hartmann’s procedure still remains an option in very elderly patients.