The incidence and mortality rate of cervical cancer ranks fourth in the world among the malignant tumors of women in the world. [1] With the emergence of aging society, the new cases of cervical cancer in the elderly are gradually increasing,[14]. Therefore, it is of great significance to explore the risk factors and appropriate treatment for the elderly cervical cancer.
The prognosis of cervical cancer is multifactorial. Yang HS et al. [15] concluded that the independent prognostic factors in stage IB-IIA cervical cancer under postoperative were number of complications, surgical methods, neoadjuvant treatment, lymph node metastasis, postoperative treatment, lymphovascular space invasion (LVSI). In our study, the five factors affecting the prognosis of the elderly cervical cancer received radiotherapy were tumor size, HB value, chemotherapy, and pelvic lymph node metastasis. The univariate analysis showed that clinical stage was significantly associated with prognosis (P < 0.001). However, the Cox multivariate analysis of the present study showed no such association. This may be due to selection bias related to the small sample size of a retrospective analysis, or the advanced stage of these elderly patients.
Radiotherapy is the best choice for the elderly with cervical cancer because of their poor physical condition and comorbidities such as hypertension, diabetes, and heart disease. Sharma et al. [16] also reported the advantages of radiotherapy in the elderly with cervical cancer. In our study, the survival of patients received IMRT was similar to that of those with conventional radiotherapy (P = 0.189).
Lin Y et al. [17] reported that the rates of adverse reactions such as radiation cystitis, colitis, and bone marrow suppression in the IMRT group were significantly lower compared with that of the group given conventional radiotherapy. Shi et al. [18] also confirmed that the occurrence of grade 2 gastrointestinal reactions was reduced from 91–60%, and grade 3 gastrointestinal toxicity was significantly reduced from 50–11.1% compared with ventional radiotherapy (P = 0.189).
A meta-analysis by Datta et al. [19] showed that the 5-year overall survival rate of concurrent chemo-radiotherapy in locally advanced cervical cancer increased by 7.5% compared with radiotherapy alone. In our study, the 5-year survival of concurrent chemo-radiotherapy was improved by 20% (85%&65%) than that of radiotherapy alone in elderly patients (P < 0.05). However, in terms of drugs, there was no significant difference in prognosis between patients given chemotherapy with dual agents or single agents (P = 0.706).
Liu YM et al. [20] reported that anemia before radiotherapy were predictors of the OS (P = 0.008). Anemia can lead to ischemia at the site of the malignant tumor, thus reducing the local control rate of radiotherapy and chemotherapy. At the same time, hypoxia changes the local protein and genome structure of malignant tumor sites, thus improving the invasion ability of malignant tumor cells [21].High hemoglobin content can improve the oxygen supply and promote the transformation of hypoxic cells into proliferative cells, thus improving the efficacy of radiotherapy and chemotherapy in malignant tumors. In our study, 51 cases (13.86%) of moderate and severe anemia had significant influence on survival and prognosis (P < 0.001).
In pre-cervical cancer studies, SCC-Ag could effect the survival and prognosis of cervical squamous cell carcinoma. Chen et al. [22] showed that the 5-year OS and PFS of patients with SCCpre < 11.4 g/L and SCCpost < 1.9 g/L were better than the group which SCCpre > 11.4 g/L and SCCpost > 1.9 g/L. The univariate analysis showed that SCCpre < 11.4 µ g/ L was a significant prognostic indicator.
Our study showed that the correlation coefficient between tumor size and lymph node metastasis was 0.198 (P < 0.001). This result agrees with Cai J. et al’ study [23] and clinical stage also was significantly associated with lymph node metastasis (r = 0.412, P < 0.001).
Our study developed a nomogram to estimate the probability of OS for patients with staged II-III cervical cancer who received radiotherapy with or without adjuvant chemotherapy. The nomogram showed high prognostic efficacy and good reproducibility. As the score increased, OS significantly worsened. The nomogram is based on multifactorial regression analysis. The complex regression equation is transformed into visual images to make the conclusions of the prediction model more readable and convenient for doctors to evaluate patients [24–25]. In the present study, univariate and multivariate Cox regression analyses were used to establish five independent prognostic indicators (tumor size, age, chemotherapy, anemia, and pelvic lymph node metastasis), which were incorporated into a Nomogram prediction model. To evaluate the degree of differentiation of prediction models, C-index statistics and ROC curve drawing are usually used to compare and verify models [26]. In our study, the C-index of the model is 0.699 and the average AUC values for 3- and 5- year OS are 0.751 and 0.724, respectively, which indicating that the prediction model has high resolution. The calibration curve also showed that the predicted 3-year and 5-year survival rates were very close to the actual patient survival rates, suggesting that the prediction model is acceptably accurate.
The limitations of the present study are that it is a retrospective analysis based on data from a single center with a small sample. Therefore, the selection of relevant variables may be biased. Furthermore, there is no external test data to verify the nomograph. For validation, further studies are warranted to improve accuracy and popularize the model.