The size of the elderly population, especially octogenarians, has steeply increased in the past decades, according to the United Nations 2015 report. If this trend continues, in 2050, octogenarians will account for 20% of the world’s population. The term "elderly" is a subjective term, based on an interpretation of the culture that the individual lives in. The World Health Organization stratified the “old” as follows: “elderly” was older than 65 years, “young-old” was 65 to 75 years old and “old-old” was older than 75 years26. Therefore, almost all randomized controlled trials (RCT) regarding older adults are age of 80 and under. To fill this gap in high-quality studies on treatment options for octogenarian colorectal cancer patients, we
performed this meta-analysis.
Marusch and Wolters et.al reported that most elderly patients with colorectal cancer had other complications, such as cardiovascular and lung diseases; Pirrera covered similar conclusion 3 29 30.Surgical outcomes are determined by complex interactions between various factors, including patient characteristics, diagnosis, and type of surgery. The surgical risk increases with age, mainly due to frequent comorbidities and loss of cardiorespiratory reserve. Besides, the complication tolerance in older adults are poor, which increases the risk of surgery and postoperative morbidity and mortality. As we covered, octogenarian patients were associated with a high incidence of overall postoperative complications and in-hospital mortality, with a three times higher preoperative comorbidities burden than those in younger patients. The poor preoperative status may partly explain the high risk of postoperative complications.
Unexpectedly, the postoperative complications risk in octogenarian patients is the same as in younger patients. In the subgroup analysis, except for intestinal obstruction, there is no significant differences between octogenarian patients and younger patients in surgical complications, especially in anastomotic fistula.
Anstomotic fistula is one of the most serious complications in colorectal cancer surgery. Under such circumstances, it usually requires
reintervention to resolve anstomotic fistula, sometimes these patients need to be transferred to the ICU and often leads to death. This may benefit the technical development of surgery and anesthesia.
Despite the similar surgical complications, the short-term mortality is higher in octogenarians compared to younger patients, which may indicate that this is a result of patient-related comorbidities rather than the procedure itself. On the other way, our study found that octogenarian patients manifest a higher incidence of postoperative complications in multiple systems throughout the body. This is associated with the higher possibility of preoperative comorbidities in octogenarian patients.
Speaking to long term survival outcomes, many studies have revealed the OS of octogenarians was significantly lower than that of younger patients. Additionally, the DFS between the 2 groups has been found to be quite similar, which is consistent to the previous studies31–34
Furthermore, the tumor, lymph node, and metastatic stage were reported to be independent predictors of OS, rather than sex, comorbidities, type of surgery, and complications.
On the authority of the NCCN guidelines 35, colorectal cancer patients who are clinically diagnosed as T3 or N + should receive neoadjuvant therapies. Nevertheless, it was found by researchers that the younger group received more neoadjuvant therapies ,compared to the elderly group 36 37.A series of factors, a heavy burden of comorbidities, poor tolerance of radiotherapy and chemotherapy, and lower life expectation,were regarded as the potential triggers. But it is out of expectation that the DFS between the two groups was not statistically different, indicating that standard therapies are likely to be intolerant for octogenarian patients. Hereby, personalized therapies, which is characterised by neoadjuvant therapies or palliative surgeries, may be the optimal choice for the octogenarian.
There are some limitations to our meta-analysis that should be addressed.
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The research time span is large, and the article retrieval may be incomplete, resulting in incomplete data collection.
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The included study regions were different, including 13 different countries such as the United States, Japan and the United Kingdom, and the research subjects in different regions caused large sources of heterogeneity.
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Whole included studies were retrospective researches, which were likely to cause additional selection and information bias.
(4) It is under great probability that a significant selection bias could result from comparing the incidence of postoperative complications without similar physical histories.
To draw a conclusion, it has been well demostrated in this meta-analysis that octogenarian CRC patients are vulnerable to comorbidities and high incidence of postoperative complications and mortality. Based on the survival outcomes analysis, the DFS in octogenarian or even older patients was similar to that of younger patients while the OS was significantly lower in octogenarian patients. Some of octogenarian CRC patients may benefit more from conservative treatment or palliative surgery. Risk stratification based on comorbidities and biochemical and physiological markers can act as a reference standard to help clinicians to determine whether surgery, type of surgery, and timing of surgery. Physiological age rather than actual age should determine cancer management for each individual.