Second primary malignancy risk after radiotherapy in rectal cancer survivors

Protocol-based CT-guided brachytherapy for patients with prostate cancer and previous rectal extirpation-a curative approach

OBJECTIVE

There are numerous curative treatment possibilities for prostate cancer. In patients who have undergone rectal extirpation for rectal cancer treatment, curative options are limited due to anatomic changes and previous irradiation of the pelvis. In this analysis, we validate the feasibility of CT-guided transperineal interstitial brachytherapy for this specific scenario.

PATIENTS AND METHODS

We analyzed the treatment procedures and outcomes of 5 patients with metachronic nonmetastatic prostate cancer. Ultrasound-guided brachytherapy was not possible in any of the patients. Of these 5 patients, 3 were treated for prostate cancer using temporary brachytherapy with Ir-192 only, and 2 were treated with external-beam radiation therapy and temporary brachytherapy as a boost. CT-guided brachytherapy was performed in all patients. We analyzed the feasibility, efficacy, treatment-related toxicity, and quality of life (EORTC-30, IEFF, IPSS, and ICIQ questionnaires) of the treatments.

RESULTS

Median follow-up was 35 months. Two out of five patients received boost irradiation (HDR 2 × 9 Gy, PDR 30 Gy). Three out of five patients were treated with PDR brachytherapy in two sessions up to a total dose of 60 Gy. Dosimetric parameters were documented as median values as follows: V100 94.7% (94.5-98.4%), D2bladder 64.3% (50.9-78.3%), D10urethra 131.05% (123.2%-141.2%), and D30urethra 122.45% (116.2%-129.5%). At the time of analysis, no biochemical recurrence had been documented. Furthermore, neither early nor late side effects exceeding CTCAE grade 2 were documented.

CONCLUSION

CT-guided transperineal brachytherapy of the prostate in patients with previous rectal surgery and radiation therapy is safe and represents a possible curative treatment option. Brachytherapy can be considered for patients with metachronic prostate cancer in this specific scenario, albeit preferably in experienced high-volume centers.

Analyzing risk factors for second malignancies in early gastric carcinoma from the SEER database

This retrospective study analyzed a large population of gastric cancer (GC) patients treated between 2010 and 2015 to investigate the clinical features and predictive risk factors for developing secondary primary malignancies (SPMs). The cumulative incidence of SPM was assessed using Kaplan-Meier analysis. Competing risk analyses adjusted for mortality were conducted using stratified Cox proportional hazard regression models and multivariate analyses to identify independent predictors of SPM. A total of 3289 out of 167,747 GC patients were included in the analytic cohort, with 155 patients diagnosed with SPM. Patients whose histologic type other than adenocarcinomas (AC) and signet ring cell carcinoma (SRCC) emerged as an independent risk factor for developing SPM (hazard ratio [HR] 2.262, 95% confidence interval [CI] 1.146-4.465, P = 0.019) in multivariate Cox regression analysis. The surgical method, including biopsy/local excision (HR 2.3, [CI] 1.291-4.095, P = 0.005) and subtotal/total resection ([HR] 1.947, [CI] 1.028-3.687, P = 0.041), chemotherapy ([HR] 1.527, [CI] 1.006-2.316, P = 0.047), and histologic type ([HR] 2.318, [CI] 1.193-4.504, P = 0.013)), were identified as independent risk factors in the competitive risk model. Subgroup analyses, stratified by chemotherapy, revealed an increased risk of SPM among older patients. Furthermore, a nomogram was developed and internally validated to predict the cumulative incidence of SPM in GC patients (C-index = 0.73 for 72 months). These findings suggested that in specific histologic types of GC, the lymph node infiltration region missed after local surgical resection, and concomitant chemotherapy would have an increased risk of SPM for cancer survivors.

Secondary Primary Cancer Risk After Radiation Therapy in Rectal Cancer: A Population-Based Cohort Study With Propensity Score Matching

BACKGROUND

It remains unclear whether radiation therapy (RT) has an impact on the development of secondary primary cancer (SC) in rectal cancer (RC) patients, especially within the true pelvis.

AIM

To examine the incidence of SC in a population-based cohort of RC after surgical treatment with or without radiation therapy (RT, NRT).

PATIENTS AND METHODS

The epidemiological cohort consisting of 13,919 RC patients with primary M0 stage diagnosed between 1998 and 2019 was collected from cancer registry data of Upper Bavaria. Competing risk analyses were conducted regarding the development of SC on 11 687 first malignancies, stratified by RT/NRT. A propensity score (PS) was generated by logistic regression modeling of RT to repeat competing risk analyses on a PS-matched cohort.

RESULTS

The median age (interquartile range) of the epidemiological cohort was 68.9 years (60.4-76.7). About 60.8%, were men, 38.7% had UICC III, 35.8% of tumors were localized lower than 8 cm, 41.3% underwent RT. Only 17.1% of patients older than 80 years at diagnosis received RT. In general, RT patients were 5 years younger than NRT patients (65.9 years [58.0-73.0] vs. 71.3 years [62.4-79.2], P < .0001). The 20-year cumulative incidence of SC was 16.5% in RT and 17.4% in NRT patients (P = .2298). Men with RT had a lower risk of prostate cancer (HR = 0.55, 95%CI [0.34-0.91], P = .0168). In the PS-matched cohort, RT patients had a significantly higher risk of bladder cancer during follow-up (10-year cumulative incidence of 1.1% vs. 0.6% in NRT). The direction of the RT effects in men and women and different tumor sites may cancel each other.

CONCLUSION

A protective effect of RT in rectal cancer patients on developing prostate SC by half is reproduced. Further analyses studying the long-term SC risks of RT should essentially focus on stratification by sex, and focus on more recent data.

Influence factors of the survival in colorectal cancer patients with second primary malignancy after surgery: A SEER database analysis

The survival rate is significantly reduced in patients with colorectal cancer (CRC) who developing a second primary malignancy (SPM), and however, little has known about the factors that contribute to the mortality of SPMs among CRC survivors. This study aims to explore the influence factors in both the all-cause and cancer-specific mortality of patients with SPMs after CRC surgery. Data of adult CRC patients with SPMs were extracted from the Surveillance, Epidemiology, and End Results (SEER) database in this retrospective cohort study. The associations between potential influence factors and all-cause mortality and cancer-specific mortality were explored using univariate and multivariate Cox proportional hazards analyses. The evaluation indexes were hazard ratios (HRs), and 95% confidence intervals (CIs). We also drew pie charts to respectively reflect the distributions of SPMs sites and time interval in study population. A total of 1202 (56.14%) patients died for all-cause, and 464 (21.67%) died due to CRC. The results showed that after adjusting for covariates, age, sex, marital status, T stage of CRC, second primary cancer site, stage of SPMs, grade of SPMs, TNM stage of SPMs, and time interval were associated with all-cause mortality, while marital status, stage of CRC, T stage of CRC, chemotherapy, second primary cancer site, stage of SPMs, grade of SPMs, TNM stage of SPMs, and time interval were associated with cancer-specific mortality in patients with CRC. In addition, colon (23.5%) was the most common site of SPMs, followed by digestive system (19.0%), and the time interval between CRC and SPMs in most patients was over 5 years (28.4%). Our findings may assist clinicians to identify high-risk patients for SPMs after CRC surgery. Also, the postoperative long-term follow-up and close attention on the key systems where the SPMs may occur are of great necessary in patients with CRC.

Radiation Therapy Changed the Second Malignancy Pattern in Rectal Cancer Survivors

Background and Objectives: Radiotherapy (RT) plays an important role in the treatment for locally advanced rectal cancer patients. It can bring radio exposure together with the survival benefit. Cancer survivors are generally at an increased risk for second malignancies, and survivors receiving RT may have higher risks than survivors not receiving RT. Whether the risk of an all-site second malignancy may increase after RT is still debated. This study aims to compare the second malignancy pattern in rectal cancer survivors after RT. Materials and Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used for analysis. In total, 49,961 rectal cancer patients (20-84 years of age) were identified between 2000 and 2012 from 18 SEER registries. All patients underwent surgery. The occurrence of second malignancies diagnosed after rectal cancer diagnosis was compared in patients who received and did not receive RT. The standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used. SEER*Stat was used to generate the 95% CIs for the SIR statistics using the exact method. Results: Of the total 49,961 patients, 5582 developed second malignancies. For all-site second primary malignancies, the age-adjusted SIRs were 1.14 (95% CI 1.1-1.18) and 1.00 (95% CI 0.96-1.04) in the no RT and RT groups, respectively. In 23,192 patients from the surgery-only group, 2604 had second malignancies, and in 26,769 patients who received RT, 2978 developed second malignancies. With respect to every site, the risk of secondary prostate cancer was significantly lower in the RT group (SIR = 0.39, 95% CI 0.33-0.46) than that in the surgery-only group (SIR = 1.04, 95% CI 0.96-1.12). Moreover, the risk of thyroid cancer was significantly higher in the RT group (SIR = 2.80, 95% CI 2.2-3.51) than that in the surgery-only group (SIR = 1.29, 95% CI 0.99-1.66). Conclusions: RT may change the second malignancy pattern in rectal cancer survivors; the risk of prostate cancer decreased, and the risk of thyroid cancer increased most significantly.

Sarcopenia is Associated With Oncological Prognosis and the Incidence of Secondary Cancer in Patients With Middle/Lower Rectal Cancer

OBJECTIVE

This study evaluated the clinical implications of sarcopenia for patients with rectal cancer according to cancer progression.

SUMMARY BACKGROUND DATA

The negative impact of body composition on long-term outcome has been demonstrated for various malignancies.

METHODS

We retrospectively reviewed 708 patients with rectal cancer who underwent curative resection at our institution between 2003 and 2020. Factors contributing to long-term outcomes and the incidence of secondary cancer (ISC) were analyzed. Psoas muscle mass index (PMI) was assessed using preoperative computed tomography. Sarcopenia was defined using the PMI cut-off values for Asian adults (6.36 cm²/m² for males and 3.92 cm2/m2 for females).

RESULTS

Sarcopenia was identified in 306 patients (43.2%). Sarcopenia was associated with advanced age, low body mass index, smoking history, and advanced T-stage. Multivariate analysis showed sarcopenia was an independent poor prognostic factor for OS (HR 1.71; P = .0102) and cancer-specific survival (HR 1.64; P = .0490). Patients with sarcopenia had significantly higher mortality due to cancer-related death in stages III and IV, whereas non-rectal cancer-related death, including secondary cancer, was markedly increased in stage 0-II sarcopenic rectal patients. Five-year cumulative ISC in patients with and without sarcopenia was 11.8% and 5.9%, respectively. Multivariate analysis revealed that sarcopenia was an independent predictive factor for ISC (HR 2.05; P = .0063).

CONCLUSIONS

Sarcopenia helps predict survival outcomes and cause of death according to cancer stage for patients with middle/lower rectal cancer who underwent radical surgery. Furthermore, sarcopenia increased the development of secondary cancer in those patients.

Secondary ovarian cancer after external beam radiotherapy for nonovarian pelvic malignancy

OBJECTIVE

To examine characteristics and survival of patients who developed secondary ovarian cancer after external beam radiotherapy (EBRT) for a prior nonovarian pelvic malignancy.

METHODS

This is a population-based retrospective cohort study, querying the Surveillance, Epidemiology, and End Result program from 1975 to 2016. 167,269 women who received EBRT for 7 malignancies (anus, rectum, bladder, cervix, uterus, vulva, or vagina) were examined to identify subsequent secondary ovarian cancer diagnosis after EBRT. Then, within the ovarian cancer cohort (n = 147,618), characteristics and survival of patients with secondary ovarian cancer after EBRT were compared to those with ovarian cancer who did not receive prior EBRT.

RESULTS

Following EBRT for a pelvic malignancy, 215 (1.3 per 1000) patients developed secondary ovarian cancer. Among those, the most frequent prior malignancy was cervical cancer (45.6%), followed by rectal cancer (20.9%). The median time from prior EBRT to secondary ovarian cancer was 8.8 years (interquartile range, 2.8-14.5). In multivariable analysis, patients with secondary ovarian cancer after EBRT were more likely to be older, and have a recent year of diagnosis, but less likely to have early-disease compared to ovarian cancer patients without prior EBRT (all, P < 0.05). In weighted model, patients with secondary ovarian cancer after EBRT had decreased overall survival compared to those with ovarian cancer without prior EBRT (5-year rates, 19.6% versus 39.9%, hazard ratio 1.62, 95% confidence interval 1.43-1.85). Similar association was observed in ages <70, ≥70, White, non-White, early-disease, and advanced-disease in sensitivity analyses.

CONCLUSION

Radiotherapy-related secondary ovarian cancer may be associated with decreased overall survival.

Postoperative radiotherapy might be a risk factor for second primary lung cancer: A population-based study

BACKGROUND

Surgery is the main curative therapeutic strategy for patients with initial primary lung cancer (IPLC). Most international guidelines recommend regular follow-ups after discharge to monitor patients for tumor recurrence and metastasis. As the overall survival (OS) in patients with lung cancer improves, their risk of secondary primary lung cancer (SPLC) increases. Previous studies on such patients lack separate assessment of different survival outcomes and evaluation of high-risk factors for SPLC. Therefore, we aimed to determine the correlation between high-risk factors and causes of death in patients with SPLC, based on the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

We screened the SEER database for patients with IPLC and SPLC from 2004 to 2015 and included only patients who underwent surgery since the IPLC and in whom the cancer was pathologically verified of an International Classification of Diseases grade of 0-3 and to be non-small-cell lung cancer. The standardized incidence ratio (SIR) was calculated between variables and SPLC. Multivariable Cox proportional-hazards regression analyses were conducted to calculate the correlation of different variables with overall survival (OS) and cancer-specific survival (CSS). A competing-risk model was conducted for SPLC. The effect of baseline bias on survival outcomes by performing propensity score matching analysis in a 1: 6 ratio (SPLC: IPLC).

RESULTS

For patients aged 0-49 years, the overall SIR was higher in older patients, reaching a maximum of 27.74 in those aged 40-49 years, and at 11.63 in patients aged 50-59 years. The overall SIR was higher for patients who were more recently diagnosed with IPLC and increased with time after diagnosis. Male sex, SPLC (hazard ratio, 1.6173; 95% confidence interval, 1.5505-1.6869; P < 0.001), cancer grade III or IV, lower lobe of the lung, advanced stage and postoperative radiotherapy (PORT) were independently detrimental to OS. In terms of CSS, PORT was a high-risk factor.

CONCLUSIONS

Postoperative radiotherapy is a risk factor for second primary lung cancer and detrimental to overall and cancer-specific survival in patients who had initial primary lung cancer. These data support the need for life-long follow-up of patients who undergo treatment for IPLC to screen for SPLC.

Risk and prognosis of secondary bladder cancer after radiation therapy for pelvic cancer

Background

Radiation therapy (RT) is a crucial modality for the local control of pelvic cancer (PC), but the effect of pelvic RT on the development of secondary malignancy is still unclear. This study aimed to identify the relationship between radiation therapy received for the treatment of primary PC and subsequent secondary bladder cancer (SBC).

Methods

The Surveillance, Epidemiology, and End Results (SEER) database (from 1975 to 2015) was queried for PC. Fine-gray competing risk regression and Cox regression analyses were employed to assess the cumulative incidence of SBC. Poisson regression and multiple primary standardized incidence ratios (SIR) were used to evaluate the radiotherapy-associated risk for patients receiving RT. Subgroup analyses of patients stratified by latency time since PC diagnosis, calendar year of PC diagnosis stage, and age at PC diagnosis were also performed. Overall survival (OS) was compared among different treatment groups with SBC by Kaplan–Meier analysis.

Results

A total of 318,165 observations showed that the primary cancers were located in pelvic cavity, 256,313 patients did not receive radiation therapy (NRT), 51,347 patients who underwent external beam radiation therapy (EBRT), and 10,505 patients receiving a combination of EBRT and brachytherapy (EBRT–BRT) who developed SBC. Receiving two types of radiotherapy was strongly consistent with a higher risk of developing SBC for PC patients in Fine-Gray competing risk regression (NRT vs. EBRT, adjusted HR= 1.71, 95% CI: 1.54-1.90, P&lt;0.001; NRT vs. EBRT–BRT, adjusted HR= 2.16, 95% CI: 1.78-2.63, P&lt;0.001). The results of the dynamic SIR and Poisson regression analysis for SBC revealed that a slightly increased risk of SBC was observed after RT in the early latency and was significantly related to the variations of age at PC diagnosis and decreased with time progress. For OS, the SBC after NRT, SBC after EBRT, and SBC after EBRT-BRT of 10-year survival rates were 37.9%, 29.2%, and 22.2%, respectively.

Conclusion

Radiotherapy for primary PC was associated with higher risks of developing SBC than patients unexposed to radiotherapy. Different pelvic RT treatment modalities had different effects on the risk of SBC.

Risk and prognosis of secondary bladder cancer after post-operative radiotherapy for gynecological cancer

The aim of this study was to investigate the impacts of radiation therapy (RT) on the occurrence risk of secondary bladder cancer (SBC) and on the patients' survival outcome after being diagnosed with gynecological cancer (EC). The data was obtained from the SEER database between 1973 and 2015. Chi-squared test was used to compare the clinicopathological characteristics among the different groups. Fine and Gray's competing risk model was used to assess the cumulative incidence and occurrence risk of SBC in GC survivors. Kaplan-Meier method was utilized for survival analysis. A total of 123,476 GC patients were included, among which 31,847 (25.8%) patients received RT while 91629 (74.2%) patients did not. The cumulative incidence of SBC was 1.59% or 0.73% among patients who had received prior GC specific RT or not, respectively. All EBRT (standardized incidence ratio (SIR) =2.49, 95% CI [2.17-2.86]), brachytherapy (SIR =1.96, 95% CI [1.60-2.38]), and combinational RT modality groups (SIR =2.73, 95% CI [2.24-3.28]) had dramatically higher SBC incidence as compared to the US general population. Receiving EBRT (HR = 2.83, 95% CI [2.34-3.43]), brachytherapy (HR = 2.17, 95% CI [1.67-2.82]), and combinational RT modality (HR = 2.97, 95% CI [2.34-3.77]) were independent risk factors for SBC development. Survival detriment was observed in SBC patients who received RT after GC diagnosis, as compared to those who did not receive RT. In conclusion, patients who underwent RT after GC had an increased risk of developing bladder as a secondary primary cancer. A long-term surveillance for SBC occurrence is necessary for GC patients who have received prior RT.

Increased risk of secondary bladder cancer after radiation therapy for endometrial cancer

To investigate the effect of radiation therapy (RT) after endometrial cancer (EC) diagnosis on the risk of occurring secondary bladder cancer (SBC) as well as on the survival outcome of those patients who suffered with SBC. Data was extracted from the Surveillance, Epidemiology, and End Results database between 1973 and 2015. Chi-squared test was utilized to compare clinicopathological characteristics among different groups. The Fine and Gray's competing risk model was utilized to assess cumulative incidence and risk of occurring SBC in EC survivors. The Kaplan-Meier method and the Cox regression model were used for survival analysis. As a result, a total of 108,060 EC patients were included, among which 37,118 (34.3%) patients received RT while others did not. The incidence of SBC was 1.31%, 1.76% and 0.96% among patients who received prior brachytherapy, external-beam radiotherapy (EBRT) and others, respectively. Both of the EBRT (standardized incidence ratio (SIR) = 2.24, 95% CI [1.94-2.58]) and brachytherapy (SIR = 1.76, 95% CI [1.44-2.13]) group had a higher incidence of SBC than the general population in USA. The competing risk analysis demonstrated that receiving EBRT (HR = 1.97, 95% CI [1.64-2.36]) or brachytherapy (HR = 1.46, 95% CI [1.14-1.87]) were all independent risk factors for developing SBC. A survival detriment was only observed in SBC patients who received prior EBRT after EC diagnosis, but not for brachytherapy, when compared with those who did not undergo RT. Additionally, there were no significant survival differences between primary bladder cancer and SBC with or without prior RT history. Patients who underwent RT after EC had an increased risk of developing bladder cancer as secondary primary cancer. The prognosis of these SBC patients varied depending on types of RT that received after EC diagnosis.

Preoperative Short-Course Radiotherapy and Surgery versus Surgery Alone for Patients with Rectal Cancer: A Propensity Score-Matched Analysis at 18-Year Follow-Up

A significant problem for long-term rectal cancer survivors may be the late toxicity of radiotherapy. It creates the possible risk of developing second primary malignancy and a theoretical decrease in overall survival. This study aimed to assess the influence of short-course preoperative radiotherapy in patients with locally advanced rectal cancer on overall survival, local recurrence rate, and second malignancy at 18-year follow-up. The rectal cancer trial was conducted in a single tertiary center between February 1992 and June 2006. A total of 389 patients with locally advanced rectal cancer (cT2-cT4, cN0/+, cM0) were included in the study. Preoperative radiotherapy was conducted in 148 patients and 241 patients underwent surgery alone. The propensity-matched group consisted of 105 patients operated on after radiotherapy and 105 controls. The number of local recurrences was 7 (6.7%) in the preoperative radiotherapy group and 22 (21%) in the surgery alone group (p = 0.016). The 18-year survival analysis showed no survival benefit in the preoperative radiotherapy group (38% versus 48%, p = 0.107) but improved recurrence-free survival (81% versus 58%, p = 0.001). The preoperative short-course radiotherapy significantly decreases the risk of local recurrence in locally advanced rectal cancer and may improve recurrence-free survival without an increased risk of second primary malignancy.

Identification of Patients with Locally Advanced Rectal Cancer in Whom Preoperative Radiotherapy Can Be Omitted: A Multicenter Retrospective Study at Yokohama Clinical Oncology Group (YCOG1307)

Objectives:

The present study aimed to identify patients with locally advanced rectal cancer in whom preoperative radiotherapy (RT) can be omitted.

Methods:

This study was a retrospective multi-institutional study for patients with pathological stage II and III rectal cancer who underwent surgery without preoperative therapy between January 2008 and December 2012. Clinicopathological factors were examined by univariate and multivariate analyses to clarify independent risk factors of local recurrence (LR).

Results:

The 5-year cumulative local recurrence rate (LRR) of 815 patients was 11.2%. Independent predictive factors of LR were determined by a multivariate analysis to be a tumor location of <10 cm from the anal verge, a tumor diameter of ≥50 mm, undifferentiated histological type, and advanced T-N substage (T3N+ or T4Nany). In lower rectal cancer located <10 cm from the anal verge (n = 510), the 5-year cumulative LRR of patients without any remaining three factors was 4.4%, with one factor was 13.0%, with two factors was 22.2%, and with all three factors was 41.6%.

Conclusions:

Preoperative RT may be omitted in patients with lower rectal cancer with no risk factors. However, in addition to the present risk factors, we need to further examine the extramural vascular invasion (EMVI) status and circumferential resection margin (CRM) using magnetic resonance imaging (MRI) findings.

The trial was registered with UMIN Clinical Trails Registry, number 000006039.

Risk and Prognosis of Secondary Bladder Cancer After Radiation Therapy for Rectal Cancer: A Large Population-Based Cohort Study

Background

Although radiation therapy (RT) improves local control for rectal cancer (RC), the long-term risks from RT, including development of a secondary malignancy, are controversial. The risk and prognosis of secondary bladder cancer (SBC) in RC patients undergoing RT have not been adequately studied. Our goal is to investigate the impact of RT on the risk of developing SBC and assess their survival outcomes.

Methods

This large population-based study included RC patients as their initial primary cancer from nine registries of the Surveillance, Epidemiology and End Results (SEER) database between 1973 and 2015. The cumulative incidence of SBC was assessed by using Fine and Gray's competing risk regression. The standardized incidence ratio (SIR) was used to compare the incidence of SBC in RC survivors to the US general population. The Kaplan-Meier method was used to evaluate the 10-year overall survival (OS) and 10-year cancer specific survival (CSS) for patients with SBC.

Results

Of 74,646 RC patients, 24,522 patients were treated with surgery and RT and 50,124 patients were treated with surgery alone. The incidence of SBC was 1.85% among patients who received RT and 1.24% among patients who did not. The incidence of SBC in RC patients who received RT was higher than the US general population (SIR, 1.35; 95% CI, 1.19-1.53, P<0.05), and decreased with increasing age at diagnosis, and increased with time since diagnosis. In competing risk regression analysis, undergoing RT was associated with a higher risk of SBC (hazard ratio [HR], 1.443, 95% confidence interval [CI], 1.209-1.720; P<0.001). The results of the dynamic SIR for SBC revealed that a slightly increased risk of SBC was observed after RT in the early latency, and was significantly related to the variations of age at RC diagnosis and decreased with time progress. The 10-year OS and CSS among SBC patients after RT were comparable to SBC patients after NRT.

Conclusion

Radiation was associated with an increased risk of developing SBC in RC patients, and special attention should be paid to the surveillance of these patients.

Association of Radiotherapy for Rectal Cancer and Second Gynecological Malignant Neoplasms

IMPORTANCE

Radiotherapy is a common treatment for rectal cancer, yet the risk of second gynecological malignant neoplasms (SGMNs) in patients with rectal cancer undergoing radiotherapy have not been adequately studied.

OBJECTIVE

To investigate the association between radiotherapy and the risk of individual types of SGMN in patients with rectal cancer and assess survival outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A large population-based cohort study was designed to identify the risk of SGMNs in patients with rectal cancer diagnosed from January 1973 to December 2015. The statistical analysis was conducted from September 2019 to April 2020. The study was based on the 9 cancer registries of Surveillance, Epidemiology, and End Results database. A total of 20 142 female patients with rectal cancer in localized and regional stage were included.

EXPOSURE

Receipt of neoadjuvant radiotherapy for rectal cancer.

MAIN OUTCOMES AND MEASURES

The development of an SGMN defined as any type of GMN occurring more than 5 years after the diagnosis of rectal cancer. The cumulative incidence of SGMNs was estimated by Fine-Gray competing risk regression. Poisson regression was used to evaluate the radiotherapy-associated risk for SGMNs in patients undergoing radiotherapy vs patients not undergoing radiotherapy. The Kaplan-Meier method was used to assess the survival outcomes of patients with SGMNs.

RESULTS

Of 20 142 patients, 16 802 patients (83.4%) were White and the median age was 65 years (interquartile range, 54-74 years). A total of 5310 (34.3%) patients were treated with surgery and radiotherapy, and 14 832 (65.7%) patients were treated with surgery alone. The cumulative incidence of SGMNs during 30 years of follow-up was 4.53% among patients who received radiotherapy and 1.53% among patients who did not. In competing risk regression analysis, undergoing radiotherapy was associated with a higher risk of developing cancer of the uterine corpus (adjusted hazard ratio, 3.06; 95% CI, 2.14-4.37; P < .001) and ovarian cancer (adjusted hazard ratio, 2.08; 95% CI, 1.22-3.56; P = .007) compared with those who did not receive radiotherapy. The dynamic radiotherapy-associated risks (RR) for cancer of the uterine corpus significantly increased with increasing age at rectal cancer diagnosis (aged 20-49 years: adjusted RR, 0.79; 95% CI, 0.35-1.79; P = .57; aged 50-69 years: adjusted RR, 3.74; 95% CI, 2.63-5.32; P < .001; aged ≥70 years: adjusted RR, 5.13; 95% CI, 2.64-9.97; P < .001) and decreased with increasing latency since rectal cancer diagnosis (60-119 months: adjusted RR, 3.22; 95% CI, 2.12-4.87; P < .001; 120-239 months: adjusted RR, 2.72; 95% CI, 1.75-4.24; P < .001; 240-360 months: adjusted RR, 1.95; 95% CI, 0.67-5.66; P = .22), but the dynamic RR for ovarian cancer increased with increasing latency since rectal cancer diagnosis (60-119 months: adjusted RR, 0.70; 95% CI, 0.26-1.89; P = .48; 120-239 months: adjusted RR, 2.26; 95% CI, 1.09-4.70; P = .03; 240-360 months: adjusted RR, 11.84; 95% CI, 2.18-64.33; P = .004). The 10-year overall survival among patients with radiotherapy-associated cancer of the uterine corpus was significantly lower than that among matched patients with primary cancer of the uterine corpus (21.5% vs 33.6%; P = .01).

CONCLUSIONS AND RELEVANCE

Radiotherapy for rectal cancer was associated with an increased risk of cancer of the uterine corpus and ovarian cancer. Special attention should be paid to reduce radiotherapy-associated SGMNs and improve their prognosis.

[Urinary bladder cancer as a late sequela of spinal cord injury : Decision-making aids for assessment of this causal association]

BACKGROUND

There is to date no convincing literature that has assessed the association between traumatic spinal cord injury (SCI) and the later development of urinary bladder cancer. The aim of this work is to present medical experts as well as the national accident insurance and the social courts decision-making aids based on the latest medical scientific knowledge, for assessment of this causal association.

MATERIALS AND METHODS

A study conducted between April 1998 and March 2017 in the BG Trauma Hospital Hamburg forms the basis for the decision-making aids. Urinary bladder cancer was diagnosed in 32 out of 6432 treated outpatient and inpatient SCI patients. Furthermore, relevant published literature was taken into consideration for the decision-making aids.

RESULTS

It was found that urinary bladder cancer in SCI patients occurs at a considerably younger age as compared to the general population, more frequently shows muscle invasive carcinoma with a higher grade at first diagnosis and a higher proportion of the more aggressive squamous cell carcinoma than that of the general population. Correspondingly, the survival time is extremely unfavorable. For medical experts a matrix was compiled where the various influencing factors, either for or against the recognition of an association between SCI and urinary bladder cancer, were weighted according to their relevance.

CONCLUSION

The results showed that urinary bladder cancer in SCI patients differs considerably from that of able-bodied patients. These differences drastically shorten the survival time. A study on patients with spina bifida, i.e., a congenital spinal cord disorder, corroborates these observations. They indicate histopathological differences that have so far been intangible.

Prediction of Recurrence-associated Death from Localized Prostate Cancer with a Charlson Comorbidity Index-reinforced Machine Learning Model

Research has failed to resolve the dilemma experienced by localized prostate cancer patients who must choose between radical prostatectomy (RP) and external beam radiotherapy (RT). Because the Charlson Comorbidity Index (CCI) is a measurable factor that affects survival events, this research seeks to validate the potential of the CCI to improve the accuracy of various prediction models. Thus, we employed the Cox proportional hazard model and machine learning methods, including random forest (RF) and support vector machine (SVM), to model the data of medical records in the National Health Insurance Research Database (NHIRD). In total, 8581 individuals were enrolled, of whom 4879 had received RP and 3702 had received RT. Patients in the RT group were older and exhibited higher CCI scores and higher incidences of some CCI items. Moderate-to-severe liver disease, dementia, congestive heart failure, chronic pulmonary disease, and cerebrovascular disease all increase the risk of overall death in the Cox hazard model. The CCI-reinforced SVM and RF models are 85.18% and 81.76% accurate, respectively, whereas the SVM and RF models without the use of the CCI are relatively less accurate, at 75.81% and 74.83%, respectively. Therefore, CCI and some of its items are useful predictors of overall and prostate-cancer-specific survival and could constitute valuable features for machine-learning modeling.

Increased risk of pelvic fracture after radiotherapy in rectal cancer survivors: A propensity matched study

To determine whether radiotherapy (RT) can increase pelvic fracture risk in rectal cancer survivors. Rectal cancer patients who underwent curative surgery between 1996 and 2011 in Taiwan were retrospectively studied using the National Health Insurance Research Database (NHIRD) of Taiwan. ICD‐9 Codes 808, 805.4‐805.7, 806.4‐806.7, and 820 (including pelvic, sacrum, lumbar, and femoral neck fracture) were defined as pelvic fracture. Propensity scores for RT, age, and sex were used to perform one‐to‐one matches between the RT and non‐RT group. Risks of pelvic and arm fractures were compared by multivariable Cox regression. Of the 32 689 patients, 7807 (23.9%) received RT, and 1616 suffered from a pelvic fracture (incidence rate: 1.17/100 person‐years). The median time to pelvic fracture was 2.47 years. After matching, 6952 patients each in the RT and non‐RT groups were analyzed. RT was associated with an increased risk of pelvic fractures in the multivariable Cox model (hazard ratio (HR): 1.246, 95% confidence interval (CI): 1.037‐1.495, P = 0.019) but not with arm fractures (HR: 1.013, 95% CI: 0.814‐1.259, P = 0.911). Subgroup analyses revealed that RT was associated with a higher pelvic fracture rate in women (HR: 1.431, 95% CI: 1.117‐1.834) but not in men, and the interaction between sex and RT was significant (P = 0.03). The HR of pelvic fracture increased 2‐4 years after RT (HR: 1.707, 95% CI: 1.150‐2.534, P = 0.008). An increased risk of pelvic fracture is noted in rectal cancer survivors, especially women, who receive RT.