| Objective:To estimate the treatment patterns for patients with locally advanced rectal cancer(LARC)aged ≥70 years in the Second Affiliated Hospital of Soochow University,and compare them with the data from the same period in the Surveillance,Epidemiology,and End Results(SEER)database.To analyze the impact of clinical factors,especially patterns of treatment,on the overall survival(OS),and select the best treatment pattern for elderly patients with LARC.To develop and validate a nomogram for individualized predicting their prognosis at last.Material&Method:We retrospectively analyzed 187 elderly patients(≥70 years)with locally advanced rectal adenocarcinoma as training cohort,who had received surgical resection in the Second Affiliated Hospital of Soochow University between January 2008 and December 2018.The demographic features,treatment patterns,clinicopathological characteristics and survival outcomes of these patients were collected,analyzed and compared with 11,347 elderly LARC patients,who underwent surgical resection between 2004 and 2016 from SEER database.Kaplan-Meier method was used to draw the survival curve and compared by log-rank test.Cox proportional hazards regression model was used for survival analysis to estimate the independent risk factors influencing on the prognosis of the patients and establish a nomogram for predicting overall survival.The nomogram was evaluated by Harrell’s concordance index(C-index),calibration curves and decision curve analysis(DCA)in both training and validation cohort.Results:1.Of the 187 elderly patients with LARC in our institution,69 were female and 118 were male,with a median age of 75 years.Nearly three-quarters of patients had at least one comorbidity,and 59.9%of patients had tumor stage Ⅲ.49.2%of patients received surgery alone,23.0%of patients received surgery combined with chemotherapy alone,and 9.1%and 18.7%of patients received neoadjuvant(chemo)radiotherapy and postoperative(chemo)radiotherapy,respectively.The median age of the SEER cohort was 77 years.Surgery alone accounted for 41.8%,and surgery combined with chemotherapy alone accounted for 11.1%.Neoadjuvant(chemo)radiotherapy and postoperative(chemo)radiotherapy were respectively accounted for 14.9%and 32.2%.The proportion of patients receiving radiation therapy in our institution was significantly lower than the SEER cohort(27.8%vs 47.1%,p<0.001).2.The 5-year OS of elderly LARC patients receiving neoadjuvant(chemo)radiotherapy in our institution is 77.1%,which is significantly higher than that of surgery combined with chemotherapy alone(61.7%),postoperative(chemo)radiotherapy(54.6%),and surgery alone(45.0%);SEER cohort survival results also show that patients receiving neoadjuvant(chemo)radiotherapy have the most significant survival advantage(5-year OS:62.6%,p<0.001).The 5-year OS of the patients who received postoperative(chemo)radiotherapy and surgery combined with chemotherapy alone were similar,54.4%and 55.9%,respectively,and 40.2%in the surgery only.The OS of the two cohorts were similar(5-year OS:53.9%vs 51.0%,p>0.05),and there was no significant difference in 5-year OS under the same treatment patten(both p>0.05).3.The univariate analysis showed that age,comorbidities,tumor stage,grade of differentiation,vascular invasion,tumor deposits,CEA group,surgical type and treatment patterns were related to the OS(p<0.15).The multivariate analysis confirmed that comorbidities,grade of differentiation,vascular invasion,tumor stage,CEA group and treatment patterns were independent prognostic factors for OS(p<0.05).4.The C-index of the nomogram model based on six independent prognostic factors for OS were as high as 0.798 and 0.690 in the training and validation cohort,respectively.The calibration curve showed a high degree of agreement between the predicted and actual survival rates and the DCA showed great clinical usefulness of the nomogram.Conclusion:The survival outcomes of elderly LARC patients in our institution are similar to the data in the SEER database at the same period,but there are still differences in the patterns of treatment.Especially in the application of radiotherapy,the proportion of patients receiving radiotherapy in our institution is significantly lower than that of American patients.The pattern of treatment is one of the independent prognostic factors for OS in elderly patients with LARC.Neoadjuvant(chemo)radiotherapy and radical surgery is still the best treatment strategy for elderly patients with LARC.Single-agent chemotherapy(Fluorouracil)may be a better choice for elderly patients.However,individual analysis and appropriate adjustments need to be made according to comorbidities and physical functions.The nomogram prognostic model including treatment patterns constructed in this study has a good ability to predict the overall survival of elderly patients with LARC,and may provide an important basis and reference for the individualized treatment and clinical trial design of elderly patients. |
