Bladder carcinoma and other second malignancies after radiotherapy for prostate carcinoma

[The issue of low doses in radiation therapy and impact on radiation-induced secondary malignancies]

Several studies have well documented that the risk of secondary neoplasms is increasing among patients having received radiation therapy as part of their primary anticancer treatment. Most frequently, radiation-induced neoplasms occur in volume exposed to high doses. However, the impact of "low" doses (<5 Gy) in radiation-induced carcinogenesis should be clinically considered because modern techniques of intensity-modulated radiation therapy (IMRT) or stereotactic irradiation significantly increase tissue volumes receiving low doses. The risk inherent to these technologies remains uncertain and estimates closely depend on the chosen risk model. According to the (debated) linear no-threshold model, the risk of secondary neoplasms could be twice higher with IMRT, as compared to conformal radiation therapy. It seems that only proton therapy could decrease both high and low doses delivered to non-target volumes. Except for pediatric tumors, for which the unequivocal risk of second malignancies (much higher than in adults) should be taken into account, epidemiological data suggest that the risk of secondary cancer related to low doses could be very low, even negligible in some cases. However, clinical follow-up remains insufficient and a marginal increase in secondary tumors could counterbalance the benefit of a highly sophisticated irradiation technique. It therefore remains necessary to integrate the potential risk of new irradiation modalities in a risk-adapted strategy taking into account therapeutic objectives but also associated risk factors, such as age (essentially), chemotherapy, or life style.

Second primary cancers after radiation for prostate cancer: a systematic review of the clinical data and impact of treatment technique

The development of a radiation induced second primary cancer (SPC) is one the most serious long term consequences of successful cancer treatment. This review aims to evaluate SPC in prostate cancer (PCa) patients treated with radiotherapy, and assess whether radiation technique influences SPC. A systematic review of the literature was performed to identify studies examining SPC in irradiated PCa patients. This identified 19 registry publications, 21 institutional series and 7 other studies. There is marked heterogeneity in published studies. An increased risk of radiation-induced SPC has been identified in several studies, particularly those with longer durations of follow-up. The risk of radiation-induced SPC appears small, in the range of 1 in 220 to 1 in 290 over all durations of follow-up, and may increase to 1 in 70 for patients followed up for more than 10 years, based on studies which include patients treated with older radiation techniques (i.e. non-conformal, large field). To date there are insufficient clinical data to draw firm conclusions about the impact of more modern techniques such as IMRT and brachytherapy on SPC risk, although limited evidence is encouraging. In conclusion, despite heterogeneity between studies, an increased risk of SPC following radiation for PCa has been identified in several studies, and this risk appears to increase over time. This must be borne in mind when considering which patients to irradiate and which techniques to employ.

Risk factors, therapy and survival outcomes of small cell and large cell neuroendocrine carcinoma of urinary bladder

The risk factors, the optimal therapy and prognostic factors contributing to poor outcomes of neuroendocrine urinary bladder carcinoma are not fully elucidated because of its rarity. We reviewed the medical records of neuroendocrine bladder carcinoma patients treated at the University of Nebraska Medical Center between 1996 and 2011. Eighteen patients, 55% female with a median age of 77 years, had stage IV disease at diagnosis in 50% of cases. There was a high prevalence of smoking (78%), medical co-morbidities (94%), prior cancer history (22%) and family history of cancer (61%). Treatment modalities included surgery (72%), platinum-based chemotherapy (50%) and/or radiation (22%). Median overall survival was 18.5 months (95% confidence interval, 7-36 months). Patients with Stage II and III cancer who underwent radical surgery with or without neoadjuvant chemotherapy had a median survival of 37 months. In addition to smoking, for the first time, our study indicates that the personal or family history of cancer may increase risk to neuroendocrine bladder cancer. Advanced age and stage at diagnosis, and the presence of multiple co-morbidities contribute to poor overall survival. Patients with early-stage disease are likely to benefit from a combination of radical surgery and platinum-based neoadjuvant chemotherapy.

A population-based comparison of second primary cancers in Germany and Sweden between 1997 and 2006: clinical implications and etiologic aspects

Second primary cancer (SPC) has become an increasing concern in cancer survivorship. Patterns of SPCs in different populations may offer clinical implications and research priorities into SPCs. This study is devoted to compare the occurrences and rank correlations of SPCs between Germany and Sweden. Patients diagnosed with 10 common first primaries between 1997 and 2006 from the Swedish Family-Cancer Database and 10 German cancer registries were included in this population-based study. Spearman's rank correlation coefficients were used to evaluate the strength of the relationship of SPCs between the German and Swedish datasets. Spearman's rank correlation coefficients suggested a strong positive correlation between the German and Swedish datasets based on the ranks of thirty possible SPCs after all selected first cancers. This was also true when we compared the rankings and proportions of the five most common SPCs after site-specific first primaries between the two populations. For kidney cancer, non-Hodgkin's lymphoma, and leukemia the components of the five most common SPCs was exactly the same. Also, the ranking and the proportions for the three most common SPCs (i.e., colorectal, bladder, and lung cancers) after prostate cancer were identical in the two populations, as were those after most other primary cancers. The strikingly consistent patterns of SPCs in the two populations provide excellent opportunities for joint studies and they also suggest that many underlying reasons for SPC may have universal and tangible causes that await mechanistic dissection.

Mortality and incidence of new primary cancers in men with prostate cancer: a Danish population-based cohort study

BACKGROUND

Prostate cancer (PC) survivors may have an increased risk of new primary cancers (NPCs) due to shared risk factors or PC-directed treatments.

METHODS

Using Danish registries, we conducted a cohort study of men with (n=30,220) and without PC (n=151,100) (comparators), matched 1:5 on age and PC diagnosis/index date. We computed incidence rates of NPCs per 10,000 person years (PY) and associated 95% confidence intervals (CI), and used Cox proportional hazards regression to compute hazard ratios (HRs) and 95%CI, adjusting for comorbidities. In order to obviate any impact of shorter survival among prostate cancer patients, we censored comparator patients when the matched prostate cancer patient died or was censored.

RESULTS

Follow-up spanned 113,487PY and 462,982PY in the PC and comparison cohorts, respectively. 65% of the cohorts were aged >70 years at diagnosis. Among PC patients, 51% had distant/unspecified stage, and 63% had surgery as primary treatment. The PC cohort had lower incidence of NPCs than their comparators. The adjusted HR of NPC among men with PC versus the comparators was 0.84 (95%CI=0.80, 0.88). Lowest HRs were among older men, those with distant stage, and were particularly evident for cancers of the brain, liver, pancreas, respiratory, upper gastrointestinal, and urinary systems.

CONCLUSIONS

We find no evidence of an increased risk of NPCs among men with PC. The deficit of NPCs among men with PC may be a true effect but is more likely due to lower levels of risk factors (e.g., smoking) in PC patients versus comparators, clinical consideration of cancers at new organs as metastases rather than new primaries, or under-recording/under-reporting of NPCs among PC patients.

Second primary cancers after radiation for prostate cancer: a review of data from planning studies

A review of planning studies was undertaken to evaluate estimated risks of radiation induced second primary cancers (RISPC) associated with different prostate radiotherapy techniques for localised prostate cancer. A total of 83 publications were identified which employed a variety of methods to estimate RISPC risk. Of these, the 16 planning studies which specifically addressed absolute or relative second cancer risk using dose-response models were selected for inclusion within this review. There are uncertainties and limitations related to all the different methods for estimating RISPC risk. Whether or not dose models include the effects of the primary radiation beam, as well as out-of-field regions, influences estimated risks. Regarding the impact of IMRT compared to 3D-CRT, at equivalent energies, several studies suggest an increase in risk related to increased leakage contributing to out-of-field RISPC risk, although in absolute terms this increase in risk may be very small. IMRT also results in increased low dose normal tissue irradiation, but the extent to which this has been estimated to contribute to RISPC risk is variable, and may also be very small. IMRT is often delivered using 6MV photons while conventional radiotherapy often requires higher energies to achieve adequate tissue penetration, and so comparisons between IMRT and older techniques should not be restricted to equivalent energies. Proton and brachytherapy planning studies suggest very low RISPC risks associated with these techniques. Until there is sufficient clinical evidence regarding RISPC risks associated with modern irradiation techniques, the data produced from planning studies is relevant when considering which patients to irradiate, and which technique to employ.

[Second neoplasm after treatment of localized prostate cancer]

INTRODUCTION

Prostate cancer (PC) treatment in early stages is radical prostatectomy (RP) or external radiotherapy (ER). There is some uncertainty regarding the development of new ER induced malignant tumors or second primary tumor (SPT), a fact influencing the choice of therapy. The purpose of this study is to determine the best therapeutic alternative for localized PC, in regards to incidence and time of development of.

MATERIAL AND METHODS

A systematic review of the literature is proposed by means of evaluation of studies conducted with localized PC and treated with RP or ER, published between 1990 and 2010. The Mega searchers used were Cochrane Library and Trip Database, and the data bases used were MEDLINE, OVID, Science Direct, SciELO and LiLACS, using MeSH terms and free words. The studies selected were analyzed using the MINCIR score of methodological quality (MQ) to compare articles with different design. The variables were considered to be number of patients treated, localization of lesions, global incidence of STP and MQ of the studies. Averages, medians and weighted averages (WA) were calculated. The study groups were compared using the 95% confidence intervals of the medians.

RESULTS

Eleven articles fulfilled the screening criteria (retrospective cohorts and case series); providing 13 series for the study. The average of MQ was 14.7 points (13 and 16 points). The most frequent localizations of STP were bladder, rectum and long. The WA of the global incidence of STP for the series was 3.6% (4.1% for ER and 2.2% RP) CONCLUSION: The information existing did not make it possible to demonstrated an association between the appearance of STP and therapies for localized PC, it even though there was a superior tendency in irradiated patients.

Second malignant neoplasms: assessment and strategies for risk reduction

Improvements in early detection, supportive care, and treatment have resulted in an increasing number of cancer survivors, with a current 5-year relative survival rate for all cancers combined of approximately 66.1%. For some patients, these survival advances have been offset by the long-term late effects of cancer and its treatment, with second malignant neoplasms (SMNs) comprising one of the most potentially life-threatening sequelae. The number of patients with SMNs is growing, with new SMNs now representing about one in six of all cancers reported to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. SMNs reflect not only the late effects of therapy but also the influence of shared etiologic factors (in particular, tobacco and excessive alcohol intake), genetic susceptibility, environmental exposures, host effects, and combinations of factors, including gene-environment interactions. For selected SMNs, risk is also modified by age at exposure and attained age. SMNs can be categorized into three major groups according to the predominant etiologic factor(s): (1) treatment-related, (2) syndromic, and (3) those due to shared etiologic exposures, although the nonexclusivity of these groups should be underscored. Here we provide an overview of SMNs in survivors of adult-onset cancer, summarizing the current, albeit limited, clinical evidence with regard to screening and prevention, with a focus on the provision of guidance for health care providers. The growing number of patients with second (and higher-order) cancers mandates that we also further probe etiologic influences and genetic variants that heighten risk, and that we better define high-risk groups for targeted preventive and interventional clinical strategies.

Secondary cancers after intensity-modulated radiotherapy, brachytherapy and radical prostatectomy for the treatment of prostate cancer: incidence and cause-specific survival outcomes according to the initial treatment intervention

Study Type--Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Radiation Therapy for prostate cancer can increase the risk for the development of second cancers after treatment. This study highlights the fact that such second cancers within the pelvis do occur but are not as common as previously reported. In this report we also note that even among patients who develop second cancers, if detected earlier, the majority are alive 5 years after the diagnosis.

OBJECTIVE

• To report on the incidence of secondary malignancy (SM) development after external beam radiotherapy (EBRT) and brachytherapy (BT) for prostate cancer and to compare this with a cohort contemporaneously treated with radical prostatectomy (RP).

MATERIALS AND METHODS

• Between 1998 and 2001, 2658 patients with localized prostate cancer were treated with RP (n = 1348), EBRT (n = 897) or BT (n = 413). • Using the RP cohort as a control we compared the incidence of SMs, such as rectal or bladder cancers noted within the pelvis, and the incidence of extrapelvic SMs.

RESULTS

• The 10-year SM-free survival for the RP, BT and EBRT cohorts were 89%, 87%, and 83%, respectively (RP vs EBRT, P = 0.002; RP vs BT, P = 0.37). • The 10-year likelihoods for bladder or colorectal cancer SM development in the RP, BT and EBRT groups were 3%, 2% and 4%, respectively (P = 0.29). • Multivariate analysis of predictors for development of all SMs showed that older age (P = 0.01) and history of smoking (P < 0.001) were significant predictors for the development of a SM, while treatment intervention was not found to be a significant variable. • Among 243 patients who developed a SM, the 5-year likelihood of SM-related mortality among patients with SMs in the EBRT and BT groups was 43.7% and 15.6%, respectively, compared with 26.3% in the RP cohort; P = 0.052).

CONCLUSIONS

• The incidence of SM after radiotherapy was not significantly different from that after RP when adjusted for patient age and smoking history. • The incidence of bladder and rectal cancers was low for both EBRT- and BT-treated patients. • Among patients who developed a SM, the likelihood of mortality related to the SM was not significantly different among the treatment cohorts.

Secondary malignancies following radiotherapy for prostate cancer

Human exposure to sources of radiation as well as the use of radiation-derived therapeutic and diagnostic modalities for medical reasons has been ongoing for the last 60 years or so. The carcinogenetic effect of radiation either due to accidental exposure or use of radiation for the treatment of cancer has been undoubtedly proven during the last decades. The role of radiation therapy in the treatment of patients with prostate cancer is constantly increasing as less-invasive treatment modalities are sought for the management of this widely, prevalent disease. Moreover the wide adoption of screening for prostate cancer has led to a decrease in the average age that patients are diagnosed with prostate cancer. Screening has also resulted in the diagnosis of low-grade, less-aggressive prostate cancers which would probably never lead to complications or death from the disease. Radiotherapy for prostate cancer has been linked to the late occurrence of second malignancies both in the true pelvis and outside the targeted area due to low-dose radiation scatter. Secondary malignancies following prostate irradiation include predominantly bladder cancer and, to a lesser extent, colon cancer. Those secondary radiation-induced bladder tumors are usually aggressive and sometimes lethal. Care should be given to the long-term follow up of patients under radiation therapy for prostate cancer, while the indications for its use in certain cases should be reconsidered.

Second malignancies among elderly survivors of cancer

The U.S. population is aging, life expectancy is increasing, and cancer is a disease associated with aging. Advances in screening and therapeutics have led to a growing number of cancer survivors who are at risk for the development of secondary malignancies. Although the risks for the development of second malignancies following a first diagnosis of cancer are well described for survivors of childhood malignancies, there are fewer data for malignancies common in older adults. With the aging of the U.S. population, and with improving survival statistics in many adult malignancies, there is an increasing need to identify those second malignancies that might develop in the older adult survivor of cancer. In this paper, we describe the types and rates of second malignancies following cancers commonly seen in older adults and review the literature on these malignancies. Comparisons are made between older and younger adults with regard to the risks for developing treatment-related cancers with different modalities. Recommendations for early detection of second malignancies are summarized, though there remains an unmet need for evidence-based guidelines for screening for second malignancies in the older adult in particular.

Prostate brachytherapy and second primary cancer risk: a competitive risk analysis

PURPOSE

To assess the risk of second primary cancer (SPC) after [(125)I]iodine prostate cancer brachytherapy compared with prostatectomy and the general population.

PATIENTS AND METHODS

In a cohort consisting of 1,888 patients with prostate cancer who received monotherapy with brachytherapy (n = 1,187; 63%) or prostatectomy (n = 701; 37%), SPC incidences were retrieved by linkage with the Dutch Cancer Registry. Standardized incidence rates (SIRs) and absolute excess risks (AERs) were calculated for comparison.

RESULTS

A total of 223 patients were diagnosed with SPC, 136 (11%) after brachytherapy and 87 (12%) after prostatectomy, with a median follow-up of 7.5 years. The SIR for all malignancies, bladder cancer, and rectal cancer were 0.94 (95% CI, 0.78 to 1.12), 1.69 (95% CI, 0.98 to 2.70), and 0.90 (95% CI, 0.41 to 1.72) for brachytherapy and 1.04 (95% CI, 0.83 to 2.28), 1.82 (95% CI, 0.87 to 3.35), and 1.50 (95% CI, 0.68 to 2.85) for prostatectomy, respectively. Bladder SPC risk was significantly increased after brachytherapy for patients age 60 years or younger (SIR, 5.84; 95% CI, 2.14 to 12.71; AER, 24.03) and in the first 4 years of follow-up (SIR, 2.14; 95% CI, 1.03 to 3.94; AER, 12.24). Adjusted for age, the hazard ratio (brachytherapy v prostatectomy) for all SPCs combined was 0.87 (95% CI, 0.64 to 1.18).

CONCLUSION

Overall, we found no difference in SPC incidence between patients with prostate cancer treated with prostatectomy or brachytherapy. Furthermore, no increased tumor incidence was found compared with the general population. We observed a higher than expected incidence of bladder SPC after brachytherapy in the first 4 years of follow-up, probably resulting from lead time or screening bias. Because of power limitations, a small increased SPC risk cannot be formally excluded.

Association of diagnostic radiation exposure and second abdominal-pelvic malignancies after testicular cancer

PURPOSE

The evidence associating cancer risk with diagnostic radiation exposure is unclear. Men recovering from low-grade testicular cancer frequently undergo serial abdominal-pelvic computerized tomography (CT) scanning to monitor for recurrent disease.

METHODS

We used population-based administrative data sets to identify every incident case of testicular cancer between 1991 and 2004 in Ontario, Canada. We excluded those with previous cancer, concurrent radiation therapy, retroperitoneal lymph node dissection, or fewer than 5 years observation. Patients were observed until the occurrences of death or development of a second abdominal-pelvic malignancy or until December 31, 2009.

RESULTS

A total of 2,569 men (mean age, 34.7 years; standard deviation, 10.2) were observed for a median of 11.2 years (interquartile range [IQR], 8.3 to 14.3). During the first 5 years after diagnosis, men underwent a median of 10 computed tomography (CT) scans (IQR, 4 to 18) of the abdominal-pelvic area, and they were exposed to a median of 110 mSv of radiation from radiologic investigations (IQR, 44 to 190). After this, 14 men were diagnosed with a second abdominal-pelvic malignancy (rate, five per 10,000 patient-years observation, 95% CI, three to eight); the most common diagnoses were colorectal and kidney malignancies. Radiation exposure was not associated with an excess risk of second cancers (hazard ratio per 10 mSv increase, 0.99; 95% CI, 0.95 to 1.04). This association did not change if men observed for fewer than 5 years were included in the analysis (hazard ratio, 1.00; 95% CI, 0.96 to 1.04).

CONCLUSION

Second malignancies of the abdomen-pelvis are uncommon in men with low-grade testicular cancer. In this study, the risk of second cancer was not associated with the amount of diagnostic radiation exposure.

Predictors in the outcome of 125I brachytherapy as monotherapy for prostate cancer

A number of different prostate cancer treatment modalities exist. Nomograms are used to assist clinicians and patients in choosing the most appropriate treatment. However, the predicted outcome for (125)I brachytherapy is much worse than what would be expected considering the actual survival rates. This underestimation may result in suboptimal treatment decisions. Therefore, better predictors for outcome after (125)I brachytherapy are necessary. The following factors, which may either influence outcome or predict outcome after brachytherapy, are discussed: tumor characteristics and risk stratification, patient age at treatment, obesity, adjuvant androgen-deprivation therapy, prostate-specific antigen bounce, implantation technique and dosimetry. For the prediction of outcome after (125)I brachytherapy, as long as the quality of the implant is optimal, only high-risk prostate cancer was found to have a negative impact on outcome.

Estimate of the uncertainties in the relative risk of secondary malignant neoplasms following proton therapy and intensity-modulated photon therapy

Theoretical calculations have shown that proton therapy can reduce the incidence of radiation-induced secondary malignant neoplasms (SMN) compared with photon therapy for patients with prostate cancer. However, the uncertainties associated with calculations of SMN risk had not been assessed. The objective of this study was to quantify the uncertainties in projected risks of secondary cancer following contemporary proton and photon radiotherapies for prostate cancer. We performed a rigorous propagation of errors and several sensitivity tests to estimate the uncertainty in the ratio of relative risk (RRR) due to the largest contributors to the uncertainty: the radiation weighting factor for neutrons, the dose-response model for radiation carcinogenesis and interpatient variations in absorbed dose. The interval of values for the radiation weighting factor for neutrons and the dose-response model were derived from the literature, while interpatient variations in absorbed dose were taken from actual patient data. The influence of each parameter on a baseline RRR value was quantified. Our analysis revealed that the calculated RRR was insensitive to the largest contributors to the uncertainty. Uncertainties in the radiation weighting factor for neutrons, the shape of the dose-risk model and interpatient variations in therapeutic and stray doses introduced a total uncertainty of 33% to the baseline RRR calculation.

Relationship between radiation exposure and risk of second primary cancers among atomic bomb survivors

Radiation exposure is related to risk of numerous types of cancer, but relatively little is known about its effect on risk of multiple primary cancers. Using follow-up data through 2002 from 77,752 Japanese atomic bomb survivors, we identified 14,048 participants diagnosed with a first primary cancer, of whom 1,088 were diagnosed with a second primary cancer. Relationships between radiation exposure and risks of first and second primary cancers were quantified using Poisson regression. There was a similar linear dose-response relationship between radiation exposure and risks of both first and second primary solid tumors [excess relative risk (ERR)/Gy = 0.65; 95% confidence interval (CI), 0.57-0.74 and ERR/Gy = 0.56; 95% CI, 0.33-0.80, respectively] and risk of both first and second primary leukemias (ERR/Gy = 2.65; 95% CI, 1.78-3.78 and ERR/Gy = 3.65; 95% CI, 0.96-10.70, respectively). Background incidence rates were higher for second solid cancers, compared with first solid cancers, until about age 70 years for men and 80 years for women (P < 0.0001), but radiation-related ERRs did not differ between first and second primary solid cancers (P = 0.70). Radiation dose was most strongly related to risk of solid tumors that are radiation-sensitive including second primary lung, colon, female breast, thyroid, and bladder cancers. Radiation exposure confers equally high relative risks of second primary cancers as first primary cancers. Radiation is a potent carcinogen and those with substantial exposures who are diagnosed with a first primary cancer should be carefully screened for second primary cancers, particularly for cancers that are radiation-sensitive.

Analysis of second malignancies after modern radiotherapy versus prostatectomy for localized prostate cancer

PURPOSE

To clarify the risk of developing second primary cancers (SPCs) after radiotherapy (RT) versus prostatectomy for localized prostate cancer (PCa) in the modern era.

METHODS

The RT cohort consisted of 2120 patients matched on a 1:1 basis with surgical patients according to age and follow-up time. RT techniques consisted of conventional or two-dimensional RT (2DRT, 36%), three-dimensional conformal RT and/or intensity modulated RT (3DCRT/IMRT, 29%), brachytherapy (BT, 16%), and a combination of 2DRT and BT (BT boost, 19%).

RESULTS

The overall SPC risk was not significantly different between the matched-pair (HR 1.14, 95% CI 0.94-1.39), but the risk became significant >5years or >10years after RT (HR 1.86, 95% CI 1.36-2.55; HR 4.94, 95% CI 2.18-11.2, respectively). The most significant sites of increased risk were bladder, lymphoproliferative, and sarcoma. Of the different RT techniques, only 2DRT was associated with a significantly higher risk (HR 1.76, 95% CI 1.32-2.35), but not BT boost (HR 0.83, 95% CI 0.50-1.38), 3DCRT/IMRT (HR 0.81, 95% CI 0.55-1.21), or BT (HR 0.53, 95% CI 0.28-1.01).

CONCLUSIONS

Radiation-related SPC risk varies depending on the RT technique and may be reduced by using BT, BT boost, or 3DCRT/IMRT.

Treating prostate cancer with radiotherapy

This Review focuses on the adverse effects of radical radiotherapy for localized prostate cancer. The adverse effects are described in the context of alternative treatment modalities. First, we consider the methodological issues that make comparison between the different treatment modalities problematic. Such issues include differences in baseline levels of urinary, bowel and sexual dysfunction, the importance of using patient-reported outcomes and the distinction between actuarial and prevalence rates of treatment-related toxic effects. Second, we describe the pattern of adverse effects that occur over time after radiotherapy. Here, we focus on evidence for a beneficial effect of radiotherapy on some urinary symptoms, and the controversy regarding the risk of secondary malignancy. Third, predictors of radiation toxicity are discussed. Accurate prediction of radiotherapy toxicity would be an invaluable tool for treatment individualization. It is noteworthy that the data on the adverse effects of prostate radiotherapy necessarily relate to treatment as it was delivered in the past. It is likely that recent technical advances, such as intensity modulation and image guidance, will further improve the toxicity profile of prostate radiotherapy.

A comparative study on the risk of second primary cancers in out-of-field organs associated with radiotherapy of localized prostate carcinoma using Monte Carlo-based accelerator and patient models

PURPOSE

A physician's decision regarding an ideal treatment approach (i.e., radiation, surgery, and/or hormonal) for prostate carcinoma is traditionally based on a variety of metrics. One of these metrics is the risk of radiation-induced second primary cancer following radiation treatments. The aim of this study was to investigate the significance of second cancer risks in out-of-field organs from 3D-CRT and IMRT treatments of prostate carcinoma compared to baseline cancer risks in these organs.

METHODS

Monte Carlo simulations were performed using a detailed medical linear accelerator model and an anatomically realistic adult male whole-body phantom. A four-field box treatment, a four-field box treatment plus a six-field boost, and a seven-field IMRT treatment were simulated. Using BEIR VII risk models, the age-dependent lifetime attributable risks to various organs outside the primary beam with a known predilection for cancer were calculated using organ-averaged equivalent doses.

RESULTS

The four-field box treatment had the lowest treatment-related second primary cancer risks to organs outside the primary beam ranging from 7.3 x 10(-9) to 2.54 x 10(-5)%/MU depending on the patients age at exposure and second primary cancer site. The risks to organs outside the primary beam from the four-field box and six-field boost and the seven-field IMRT were nearly equivalent. The risks from the four-field box and six-field boost ranged from 1.39 x 10(-8) to 1.80 x 10(-5)%/MU, and from the seven-field IMRT ranged from 1.60 x 10(-9) to 1.35 x 10(-5)%/MU. The second cancer risks in all organs considered from each plan were below the baseline risks.

CONCLUSIONS

The treatment-related second cancer risks in organs outside the primary beam due to 3D-CRT and IMRT is small. New risk assessment techniques need to be investigated to address the concern of radiation-induced second cancers from prostate treatments, particularly focusing on risks to organs inside the primary beam.

Acute myeloid leukemia incidence following radiation therapy for localized or locally advanced prostate adenocarcinoma

INTRODUCTION

The effect of radiation therapy on acute myeloid leukemia incidence among prostate cancer patients has not been sufficiently elucidated despite evidence that acute myeloid leukemia is a consequence of therapeutic radiation in other primary malignancies. Therefore, we investigated the effect of definitive therapy with radiation therapy (external beam radiation therapy [EBRT] or brachytherapy) on acute myeloid leukemia incidence in a population-based cohort of patients with localized or locally advanced prostate cancer.

METHODS

We utilized the Surveillance, Epidemiology, and End Results database to identify a cohort of men (n=168,612) with newly diagnosed prostate adenocarcinoma between January 1988 and December 2003. Cox proportional hazard regression was used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of acute myeloid leukemia incidence following definitive therapy with EBRT alone, brachytherapy alone, or surgery alone compared to no definitive therapy (i.e. no EBRT, brachytherapy, or surgery).

RESULTS

The cohort yielded 184 acute myeloid leukemia cases during 1,064,820 person-years of follow-up after prostate adenocarcinoma diagnosis. Patients treated with EBRT had a higher adjusted relative risk of developing acute myeloid leukemia than patients treated with brachytherapy or surgery when each therapy group was compared to patients who were not treated with definitive therapy (EBRT: HR=2.05, 95% CI 1.29, 3.26; brachytherapy: HR=1.22, 95% CI 0.46, 3.22; surgery: HR=1.24, 95% CI 0.77, 1.98).

CONCLUSIONS

Our findings suggest that acute myeloid leukemia incidence is a greater concern for patients treated with EBRT than brachytherapy for localized or locally advanced prostate adenocarcinoma.

Radical cystectomy in patients previously treated for localized prostate cancer

OBJECTIVES

To present outcomes of a contemporary series of patients undergoing radical cystectomy (RC) for bladder cancer after previous treatment for localized cancer of the prostate (CaP).

METHODS

A retrospective review of more than 1000 RCs performed for bladder cancer between 1995 and 2008 identified 49 patients previously treated for localized CaP. Patients were stratified according to the type of primary therapy received for CaP: any form of primary or adjuvant radiotherapy (brachytherapy or external beam radiotherapy) versus radical prostatectomy (RP) monotherapy. Perioperative data were analyzed and compared between the 2 groups.

RESULTS

Of 49 patients, 40 (82%) underwent primary or adjuvant radiotherapy and 9 (18%) RP alone. Eleven (22%) patients received a continent diversion. Mean estimated blood loss (EBL) and hospital stay were 979 mL and 12 days, respectively. Extravesical disease (≥pT3a) was present in 23 patients (57.5%) in the radiotherapy group and in 2 patients (22%) in the RP group. Ten patients (all in the radiotherapy group) had a positive margin, 9 (90%) of whom had pathologic T4 disease. The overall major perioperative complication rate was 41%. Of the 6 patients with an ONB (all after RP), 4 had severe incontinence.

CONCLUSIONS

Patients undergoing RC after previous treatment for localized CaP are at increased risk for perioperative morbidity. Patients should be counseled that orthotopic diversion after RP may be associated with significant incontinence. Extravesical disease is more prevalent in patients treated with previous radiation. We observed a high rate of positive margins associated with pathologic T4 disease in this cohort.

Increasing age and treatment modality are predictors for subsequent diagnosis of bladder cancer following prostate cancer diagnosis

PURPOSE

To determine the effect of prostate cancer therapy (surgery or external beam irradiation, or both or none) on the actuarial incidence of subsequent bladder cancer.

METHODS AND MATERIALS

The Surveillance, Epidemiology, and End Results registry from 1973 to 2005 was analyzed. Treatment was stratified as radiotherapy, surgery, both surgery and adjuvant radiation, and neither modality. Brachytherapy was excluded.

RESULTS

In all, 555,337 prostate carcinoma patients were identified; 124,141 patients were irradiated; 235,341 patients were treated surgically; 32,744 patients had both surgery and radiation; and 163,111 patients received neither modality. Bladder cancers were diagnosed in: 1,836 (1.48%) men who were irradiated (mean age, 69.4 years), 2,753 (1.09%) men who were treated surgically (mean age, 66.9 years); 683 (2.09%) men who received both modalities (mean age, 67.4 years), and 1,603 (0.98%) men who were treated with neither modality (mean age, 71.8 years). In each treatment cohort, Kaplan-Meier analyses showed that increasing age (by decade) was a significant predictor of developing bladder cancer (p < 0.0001). Incidence of bladder cancer was significantly different for either radiation or surgery alone versus no treatment, radiation versus surgery alone, and both surgery and radiation versus either modality alone (p < 0.0001). On multivariate analysis, age and irradiation were highly significant predictors of being diagnosed with bladder cancer.

CONCLUSIONS

Following prostate cancer, increasing age and irradiation were highly significant predictors of being diagnosed with bladder cancer. While use of radiation increased the risk of bladder cancer compared to surgery alone or no treatment, the overall incidence of subsequent bladder cancer remained low. Routine bladder cancer surveillance is not warranted.

New Italian guidelines on bladder cancer, based on the World Health Organization 2004 classification

OBJECTIVE To provide evidence-based recommendations on bladder cancer management METHODS A multidisciplinary guideline panel composed of urologists, medical oncologists, radiotherapists, general practitioners, radiologists, epidemiologists and methodologists conducted a structured review of previous reports, searching the Medline database from 1 January 2004 to 31 December 2008. The milestone papers published before January 2004 were accepted for analysis. The level of evidence and the grade of the recommendations were established using the GRADE system. RESULTS In all, 15 806 references were identified, 1940 retrieved, 1712 eliminated (specifying the reason for their elimination) and 971 included in the analysis, as well as 241 milestone reports. A consensus conference held to discuss the discrepancies between the scientific evidence and the clinical practice was then attended by 122 delegates of various specialities. CONCLUSION Recommendations on bladder cancer management are provided.

Impact of previous radiotherapy for prostate cancer on clinical outcomes of patients with bladder cancer

PURPOSE

The impact of prostate cancer radiotherapy on the biological behavior of bladder cancer remains unclear. We compared the outcomes of patients with bladder cancer previously treated for prostate cancer with radiotherapy vs other treatment modalities.

MATERIALS AND METHODS

We identified 144 patients diagnosed with bladder cancer between January 1992 and June 2007 with a previous prostate cancer diagnosis. Clinicopathological data and outcomes were compared between patients with irradiated (brachytherapy and/or external beam radiation therapy 83) and nonirradiated (androgen deprivation therapy, radical prostatectomy and/or surveillance 61) disease.

RESULTS

Median time between prostate and bladder cancer diagnoses was longer in the irradiated vs nonirradiated group (59 months, IQR 25 to 88, vs 24 months, IQR 2 to 87, p = 0.007). Patients in the irradiated group presented with higher tumor grade (high 92% vs 77%, p = 0.016) and had progression to higher stage disease (muscle invasive 70% vs 43%, p = 0.001) than those in the nonirradiated group. Of the patients undergoing cystectomy those previously treated with radiation had a numerically higher rate of nonorgan confined disease (75% vs 56% for nonirradiated, p = 0.1). Among all patients with bladder cancer 5-year cancer specific survival was 73% (95% CI 59-87) for irradiated vs 83% (95% CI 71-95) for nonirradiated (p = 0.07). Median followup was 53 months (IQR 24 to 75).

CONCLUSIONS

More time elapsed between prostate and bladder cancer diagnoses for patients treated with radiation, and these patients also presented with more advanced disease. Future studies are needed to further establish clinical differences in bladder cancer between irradiated and nonirradiated cases, and whether biological differences exist.

Second malignancies in high‑dose areas of previous tumor radiotherapy

PURPOSE

To characterize second tumors that developed in or near the high-dose areas of a previous radiotherapy, regarding their frequency, entities, latency, and dose dependence.

PATIENTS AND METHODS

9,995/15,449 tumor patients of the Radiation Oncology Department in Ulm, Germany, treated between 1981 and 2003, survived at least 1 year after radiotherapy. By long-term follow-up and review of treatment documentation, 100 of them were identified who developed an independent second cancer in or near the irradiated first tumor site.

RESULTS

Major primary malignancies were breast cancer (27%), lymphoma (24%), and pelvic gynecologic tumors (17%). Main second tumors were carcinomas of the upper (18%) and lower (12%) gastrointestinal tract, head and neck tumors (10%), lymphoma (10%), breast cancer (9%), sarcoma (9%), and lung cancer (8%). Overall median second tumor latency was 7.4 years (1-42 years). For colorectal cancer it was 3.5 and for leukemia 4.3 years, but for sarcoma 11.7 and for breast cancer 17.1 years. The relatively frequent second tumors of the upper gastrointestinal tract were associated with median radiation doses of 24 Gy. By contrast, second colorectal cancer and sarcoma developed after median doses of 50 Gy.

CONCLUSION

The 5- and 15-year probability to develop a histopathologically independent second tumor in or near the irradiated first tumor site, i.e., after intermediate or high radiation doses, was 0.5% and 2.2%, respectively. To identify potentially radiogenic second malignancies, a follow-up far beyond 5 years is mandatory. The incidence and potential dose-response relationship intermediate will be analyzed by a case-case and a case-control study of the Ulm data.

The risk and prophylactic management of bladder cancer after various forms of radiotherapy

PURPOSE OF REVIEW

Prostate cancer is the most common cancer diagnosed in men and remains the second most lethal malignancy. Most patients undergoing treatment elect for radical prostatectomy or radiation. As the number of patients treated has increased and survival improved, delayed complications of these modalities has assumed increased importance. Recent studies report an increased risk of certain cancers after radiation for prostate cancer. This review aims to summarize recent data.

RECENT FINDINGS

Recent studies have confirmed the association of prostate radiation with secondary cancers. The most common secondary malignancy is bladder carcinoma. We have treated 44 patients with bladder cancer who had radiation therapy for prostate cancer. At diagnosis, 60% had tumor, which invaded the bladder muscle (T2 or greater disease). The mean latency from radiation to diagnosis of bladder cancer was 5.5 years.

SUMMARY

Radiation therapy for prostate cancer is associated with an increased risk of bladder cancer. In our series, patients presented at higher stage than expected from population-based studies of bladder cancer. Patients and their physicians should be aware of such risks when choosing therapy for prostate cancer. Hematuria following radiation therapy for prostate cancer should be investigated rather than being attributed to radiation-induced cystitis.

Prostate cancer as a first and second cancer: effect of family history

BACKGROUND

Diagnosis with prostate cancer has been reported to increase the risk of subsequent tumours. However, specific data on individuals with a parental history are not available so far.

METHODS

On the basis of the nationwide Swedish Family-Cancer Database including 18,207 primary invasive prostate cancers, standardised incidence ratios (SIRs) were used to estimate the relative risks of subsequent tumours after prostate cancer in the general population and among individuals with a parental history of cancer.

RESULTS

A significantly increased SIR of colorectal cancer was found among prostate cancer patients with a parental history of colorectal cancer (2.26, 11 cases). The SIRs of parental concordant (same site) tumours after prostate cancer were also increased for urinary bladder cancer (4.42, 4 cases) and chronic lymphoid leukaemia (38.0, 2 cases).

CONCLUSION

A higher than additive and multiplicative interaction was observed between the individual history of prostate cancer and parental history of colorectal and urinary bladder cancers, although the number of cases did not permit the rejection of any interaction model. The results suggest that the occurrence of second tumours, for example bladder after prostate or prostate after bladder tumours, is mostly related to shared genetic and non-genetic risk factors rather than treatment of first cancer.

Subsequent malignant neoplasms in cancer survivors

In the past 3 decades, the number of cancer survivors in the United States has tripled, reaching approximately 10.7 million in 2004. Although cancer survivors now comprise about 3.5% of the population, subsequent malignancies among this high-risk group account for about 16% (or 1 in 6) of all cancer incidence. Multiple primary cancers can reflect the influence of antecedent cancer therapy, shared etiologic factors, environmental exposures, genetic susceptibility, lifestyle choices, other factors, and the combinations of effects, including gene-environment and gene-gene interactions. Survivors of individual types of primary cancers are at increased risk for distinctive types of subsequent neoplasms. Careful documentation of the magnitude and temporal patterns of these site-specific excess risks, as well as delineation of the contribution of treatment exposures and other factors, will facilitate the development of optimal follow-up plans. Management approaches should include patient education, screening, and prevention strategies. An improved understanding of those malignancies that are largely treatment-related will facilitate the formulation of customized therapeutic approaches for newly diagnosed cancer patients aimed at minimizing the risk of subsequent neoplasms and other late effects, without compromising cure rates.

Increased risk of colon cancer after external radiation therapy for prostate cancer

Radiotherapy can induce second cancers. Controversies still exist regarding the risk of second malignancies after irradiation for prostate cancer. We evaluated the risk of developing colon and rectum cancers after prostate cancer in irradiated and nonirradiated patients. Using data from the population-based Geneva cancer registry, we included in the study all men with prostate cancer diagnosed between 1980 and 1998 who survived at least 5 years after diagnosis. Of the 1,134 patients, 264 were treated with external radiotherapy. Patients were followed for occurrence of colorectal cancer up to 31 December, 2003. We calculated standardized incidence ratios (SIR) using incidence rates for the general population to obtain the expected cancer incidence. The cohort yielded to 3,798 person-years. At the end of follow-up 19 patients had developed a colorectal cancer. Among irradiated patients the SIR for colorectal cancer was 3.4 (95% confidence intervals [CI] 1.7-6.0). Compared to the general population, the risk was significantly higher for colon cancer (SIR = 4.0, 95% CI: 1.8-7.6), but not for rectal cancer (SIR = 2.0, 95% CI: 0.2-7.2). The risk of colon cancer was increased in the period of 5-9 years after diagnosis (SIR = 4.7, 95% CI: 2.0-9.2). The overall SIR of secondary cancer in patients treated with radiotherapy was 1.35 (p = 0.056). Nonirradiated patients did not have any increased risk of rectal or colon cancer. This study shows a significant increase of colon but not rectum cancer after radiotherapy for prostate cancer. The risk of second cancer after irradiation, although probably small, needs nevertheless to be carefully monitored.

Bladder cancer risk following primary and adjuvant external beam radiation for prostate cancer

PURPOSE

Increased rates of secondary bladder malignancies have been reported after external beam radiation therapy (EBRT) for gynecological malignancies with relative risks of 2 to 4. This study was designed to determine if there was an increase in bladder cancer after EBRT for prostate cancer.

MATERIALS AND METHODS

We retrospectively reviewed the Mayo Clinic Cancer Registry for patients who received EBRT for prostate cancer (1980 to 1998). Patients diagnosed with bladder cancer were identified. Comparative incidence rates were obtained from the national Surveillance, Epidemiology and End Results database. Subset analysis included patients treated with adjuvant radiation and those residing locally. Medical histories of patients with bladder cancer were reviewed.

RESULTS

A total of 1,743 patients received EBRT for prostate cancer at our institution. In more than 12,353 man-years of followup no increase in bladder cancer risk was encountered. Subset analysis of men who received adjuvant radiation demonstrated that the relative risk of bladder cancer was increased but was not statistically significant. When the analysis was restricted to patients residing in the local area, the number of patients in whom subsequent bladder cancer developed was similar to Surveillance, Epidemiology and End Results rates. However, in the adjuvant radiation subset there was a statistically significant increase in subsequent bladder cancer. Patients in whom bladder cancer develops after EBRT often present with low grade disease but many have recurrence and progression.

CONCLUSIONS

This retrospective review suggests there is not evidence of increased risk of bladder cancer after radiation therapy, assuming unbiased followup and complete ascertainment of cases. The natural history of bladder cancer in this population does not seem to be altered by a history of radiation.