With the continuous improvement of sanitary conditions and dietary habits, the world’s older population (aged 65 and over) continues to grow at an unprecedented rate, especially in developing countries [14]. Yet, with age, the incidence of cancer has also been drastically increasing.
Colorectal cancer is the third most common cause of cancer morbidity in both men and in women. The incidence of colorectal cancer in the population over 75 years is at about 40 to 50 per 100,000 persons compared to about 5 to 20 per 100,000 in persons 60–65 years [15]. Radical surgery is still considered the main treatment for this type of malignancy. However, with the increase of age, the body’s reserve capacity gradually decreases, resulting in drastically reduced tolerance to surgery. Devoto et al [16] found that the postoperative mortality and complication rate was significantly increased in patients over 70 years old who undergo colorectal cancer surgery. Moreover, Arenal-Vera and colleagues showed that among patients who were 70 years old or older, the 30-day mortality rate after colorectal cancer was about 6%, and about 20% of patients had one or more complications [17].
Laparoscopic surgery has shown similar long-term efficacy as open surgery in the treatment of colorectal tumors [18]. Yet, compared to open surgery, laparoscopic surgery has been associated with less trauma and lower postoperative stress. In addition, lower C-reactive protein and interleukin-6 levels were found in those who underwent laparoscopic surgery [19]. However, considering the long operation time and the risk of reduced cardiac output and postoperative atelectasis caused by pneumoperitoneum, the application of laparoscopic surgery in older patients with cancer is still limited [20]. Thus, data on laparoscopic rectal cancer surgery in older patients are limited.
In this study, we examined laparoscopic efficacy compared to open rectal cancer surgery in patients aged 70 years and older. Those who did not receive neoadjuvant therapy, emergency surgery, and radical surgery were selected. The surgical method was used as the grouping basis, and age, gender, BMI, ASA, and TNM stages were used as covariables to calculate the propensity score. The patients with the closest scores in the two groups were paired for comparison. This made the comparability of the data more significant and illustrative.
Over the last 5 years, 671 rectal cancer surgeries were performed in our hospital, and 198 cases were over 70 years old. Among 198 cases, 63 cases underwent open surgery, and 135 cases underwent laparoscopic surgery. After the screening for exclusion and inclusion criteria and matching, 51 pairs of data were obtained. No difference in age, gender, BMI, ASA, and TNM staging were found between groups. Francesco et al [21] compared rectal cancer patients over 80 years old with those between 60 and 69 years old and found that the average CCI of patients over 80 years old was 7, and the average CCI of patients aged 60–69 years old was 4 (P = 0.001). The ASA score in the older age group was also significantly higher. These data are consistent with our results. Only 1/4 of patients in the two groups (25.5% vs. 23.5%) had no combined disease (CCI = 0). The two groups' ASA scores were also higher, which indicated that older patients had more comorbidities and had poor physical fitness. This was also the main reason for the high risk of surgery.
Previous studies had shown that laparoscopic rectal surgery has obvious minimally invasive advantages compared with open surgery. The patients who underwent laparoscopy showed less intraoperative bleeding, faster recovery of gastrointestinal function, and shorter hospital stay [22]. In this study, we observed a similar phenomenon in older patients. Patients in the LS group had less intraoperative blood loss, faster recovery of intestinal function, early first exhaust time, less need for postoperative analgesics, and shorter hospital stay. This suggested that in older patients with rectal cancer, laparoscopic surgery may lead to less stress, less pain, and faster recovery. However, LS required a longer operation time than OS (193 minutes vs. 203 minutes) (P = 0.048). Similar results were observed in previous studies. Akiyoshi et al [23] observed consecutive cases of rectal cancer and divided them into three groups: laparoscopic surgery group with age > 75 years old (n = 44), laparoscopic surgery group with age < 75 years old (n = 228), and the open surgery group with age > 75 years old (n = 44). The results showed that laparoscopic surgery lasted significantly longer than open surgery (256 minutes vs. 196 minutes). This, in turn, indicated that laparoscopy is a highly demanding surgical technique that puts more time and energy strain on surgeons, while patients also need to undergo longer surgery and anesthesia. However, in our study, the average time difference between the two groups was only 20 minutes. We believe that this difference may be due to different surgeons, but it was more likely to indicate an improvement in technology. With the development of the technology and the improvement of the surgeon’s proficiency, LS and OS's time gap will gradually decrease. Nonetheless, laparoscopic surgery may become a preferred surgery method due to speed and efficiency.
In our study, the LS group had a lower incidence of complications than the OS group. The total cases of postoperative complications of the two groups were 11 (21.6%) and 18 (35.3%), respectively, with no statistical difference (P = 0.124). However, the tendency of anastomotic complications in the LS group was higher than that in the OS group (7.8% vs. 4%), and the tendency of incision-related complications in the OS group was higher than that in the LS group (11.7% vs. 2%). Paralytic ileus was more common in OS group (7.8% vs. 3.9%), while cardiopulmonary complications were observed in both groups (7.8% vs. 11.7%). However, no significant statistical difference between the two groups was found. In addition, no death occurred within 30 days of operation in both groups. The information obtained by this study was consistent with previous studies [16,18,23]. We observed the situation of older patients, and there were more cardiopulmonary complications after surgery, which may be related to the reduced cardiopulmonary reserve and the reduced ability to withstand surgical strikes in older patients. There were many incision-related complications in open surgery, which were associated with large incisions and longer operation time through the incision. A small incision in laparoscopic surgery was only used for specimen removal and short operation time, which may be the main reason for the fewer incision complications.
As for the anastomose-related complications, we combined TDAV and PO for further analysis. In general, the Dixon proportion in the LS group was similar to that in the OS group (30% vs. 27%, P = 0.786), and the sphincter preserving rates of the LS group and OS group were basically the same. Nevertheless, in the TDAV subgroup study, we found that in the Dixon surgery with anal preservation, for low rectal cancer with TDAV < 5 cm, more patients tended to choose LS (42.5% vs. 21.6%, P = 0.051); for middle rectal cancer with TDAV of 5–10 cm, more patients tended to choose OS (27.5% vs. 51.4%, P = 0.032); for high rectal cancer with TDAV > 10 cm, LS and OS were selected in a similar proportion (30% vs. 27%, P = 0.773). In low rectal cancer with TDAV < 5 cm, the ratio of PO of LS was higher than that of OS (52.9% vs. 37.5%, P = 0.082), but there was no significant statistical difference. In the middle rectal cancer with TDAV of 5–10 cm, the PO ratio between the two groups was similar (18.1% vs. 10.5%, P = 0.936). In high rectal cancer with TDAV > 10 cm, neither group had PO. From the above data, we can see that the tumor's location may be an important reason for the surgeon’s choice. In patients with low tumor location, surgeons were more likely to choose LS. The magnifying effect and fine operation of the laparoscope in narrow space can help surgeons to complete the operation better. In open surgery, the tumor location is generally higher, and anastomosis after resection is easier to achieve, which may account for the low anastomosis-related complications observed during open surgery. Still, the low position operation also makes suturing after anastomosis very difficult. The uncertainty of low position surgery might drive surgeons to choose PO more so as to balance and make up for the shortcomings of surgery, thus reducing the risk of surgery. This may be the reason for the high proportion of PO in LS.
An average follow-up time was 35.7 months (7–59 months). Survival rates were compared using the Log-rank test. Statistical analysis showed no statistical difference between the two groups (χ2= 0.198, P = 0.656). This indicated that there was no significant difference in the long-term effect in older patients between the two surgical methods.
This study has a few limitations. It is a retrospective, non-randomized study with relatively small sample size. Different surgeons performed the operation, which can cause some bias. For older patients with complex conditions, the choice of OS or LS and whether PO was needed was related to the operator’s assessment of the patient’s condition and personal judgment, and there was obvious uncertainty. In the future, prospective randomized studies comparing LS and OS in older patients with rectal cancer should be conducted to confirm these findings.
Our results suggested that laparoscopic rectal cancer surgery has significant short-term advantages over open surgery in older patients, as it leads to less trauma, less pain, faster recovery. Laparoscopic rectal cancer surgery was associated with a shorter postoperative hospital stay, lower incidence of postoperative complications and, as well as a longer operating time. Age did not result as a risk or limitation factor for LS. Yet, more prospective comparative studies with a larger sample size are needed to confirm these findings.