Proportion of second cancers attributable to radiotherapy treatment in adults: a cohort study in the US SEER cancer registries

Defining AML and MDS second cancer risk dynamics after diagnoses of first cancers treated or not with radiation

Risks of acute myeloid leukemia (AML) and/or myelodysplastic syndromes (MDS) are known to increase after cancer treatments. Their rise-and-fall dynamics and their associations with radiation have, however, not been fully characterized. To improve risk definition we developed SEERaBomb R software for Surveillance, Epidemiology and End Results second cancer analyses. Resulting high-resolution relative risk (RR) time courses were compared, where possible, to results of A-bomb survivor analyses. We found: (1) persons with prostate cancer receiving radiation therapy have increased RR of AML and MDS that peak in 1.5-2.5 years; (2) persons with non-Hodgkin lymphoma (NHL), lung and breast first cancers have the highest RR for AML and MDS over the next 1-12 years. These increased RR are radiation specific for lung and breast cancer but not for NHL; (3) AML latencies were brief compared to those of A-bomb survivors; and (4) there was a marked excess risk of acute promyelocytic leukemia in persons receiving radiation therapy. Knowing the type of first cancer, if it was treated with radiation, the interval from first cancer diagnosis to developing AML or MDS, and the type of AML, can improve estimates of whether AML or MDS cases developing in this setting are due to background versus other processes.

Risk of second primary malignancies in women with breast cancer: Results from the European prospective investigation into cancer and nutrition (EPIC)

Women with a diagnosis of breast cancer are at increased risk of second primary cancers, and the identification of risk factors for the latter may have clinical implications. We have followed-up for 11 years 10,045 women with invasive breast cancer from a European cohort, and identified 492 second primary cancers, including 140 contralateral breast cancers. Expected and observed cases and Standardized Incidence Ratios (SIR) were estimated using Aalen-Johansen Markovian methods. Information on various risk factors was obtained from detailed questionnaires and anthropometric measurements. Cox proportional hazards regression models were used to estimate the role of risk factors. Women with breast cancer had a 30% excess risk for second malignancies (95% confidence interval-CI 18-42) after excluding contralateral breast cancers. Risk was particularly elevated for colorectal cancer (SIR, 1.71, 95% CI 1.43-2.00), lymphoma (SIR 1.80, 95% CI 1.31-2.40), melanoma (2.12; 1.63-2.70), endometrium (2.18; 1.75-2.70) and kidney cancers (2.40; 1.57-3.52). Risk of second malignancies was positively associated with age at first cancer, body mass index and smoking status, while it was inversely associated with education, post-menopausal status and a history of full-term pregnancy. We describe in a large cohort of women with breast cancer a 30% excess of second primaries. Among risk factors for breast cancer, a history of full-term pregnancy was inversely associated with the risk of second primary cancer.

Proton beam therapy for the treatment of prostate cancer

Through unique physical dose deposition properties, proton beam therapy (PBT) potentiates radiation dose escalation to target tissue while minimizing radiation exposure to nontarget organs. Proton beam therapy has been used to treat prostate cancer for several decades; however, access to proton centers has been restricted to the limited number of proton centers. Because of recent enhancements in availability and treatment delivery systems, interest in PBT has been burgeoning among oncologists, industry experts, and prostate cancer patients. As a result, the importance of understanding the collective experience to date and technical aspects of PBT delivery has become increasingly important in cancer medicine. This review article is intended to discuss the fundamentals of PBT treatment, critically review the literature on PBT for localized prostate cancer, and describe the continued development of proton beam technology for the treatment of prostate cancer.

Incidence of Second Primary Malignancies Following Colorectal Cancer: A Distinct Pattern of Occurrence Between Colon and Rectal Cancers and Association of Co-Morbidity with Second Primary Malignancies in a Population-Based Cohort of 98,876 Patients in Taiwan

The purpose of this study is to determine the features of second primary malignancies (SPMs) among patients with prior colorectal cancer (CRC) using a nationwide population-based dataset.Patients with CRC newly diagnosed between 1996 and 2011, and >1 year of follow-up were recruited from the Taiwan National Health Insurance database. Standardized incidence ratios (SIRs) of SPMs in patients with CRC were calculated.During the 16-year study period, 4259 SPMs developed among 98,876 CRC patients. The median duration of follow-up was 4.03 years. The SIR for all SPMs was 1.13 (95% confidence interval = 1.10-1.17). Compared with the general population, a higher incidence of thyroid, prostate, ovarian, and hematologic malignancies developed among patients with colon cancer, whereas the risk for bone and soft tissue cancers increased among patients with rectal cancer. The risk for breast, bladder, kidney, lung, and uterine cancers was significantly higher in patients with colon and rectal cancers than the general population. The risk for liver and biliary tract cancers declined in patients with rectal cancer. Based on multivariate analysis among patients with CRC, age ≥70 years, men, chronic obstructive pulmonary disease (COPD), cirrhosis, and dyslipidemia were independent predictors of an SPM.In conclusion, patients with CRC were at increased risk for a second cancer. The pattern of SPMs was distinct between patients with colon and rectal cancer. Age, men, COPD, cirrhosis, and dyslipidemia were independent risk factors for SPMs. Surveillance and education should be provided for survivors with respect to risk for SPMs.

MCI extraction from Turkish galls played protective roles against X-ray-induced damage in AHH-1 cells

OBJECTIVE

To investigate the protective effects of MCI extract from Turkish galls against apoptosis induced by X-ray radiation in the AHH-1.

METHODS

The cells were divided into: control group; X-ray radiation group; MCI group, in which the confluent cells were preincubated with 5 μg/ml MCI for 2 h followed by radiation. For the radiation, cells preincubated with MCI were exposed to X-ray beams with a dose of 8 Gy in total. Cell viability, apoptosis and intracellular alteration of redox were monitored by MTT and flow cytometry.

RESULTS

Compared with radiation group, the number of cells arrested at the G0/G1 phase was significantly reduced in MCI group (P < 0.05). X-ray radiation induces remarkable apoptosis in AHH-1, which was reversed by MCI. Compared with the radiation group, the generation of intracellular reactive oxygen species (ROS) was abrogated by pre-incubation with MCI (P < 0.05). In addition, the up-regulation of procaspase-3 induced by radiation was reversed by MCI. Radiation could induce up-regulation of Bax and down-regulation of Bcl-2; however, it is reversed completely after administration of MCI. Further, the enhanced expression of ERK and JNK induced by radiation was reversed by MCI.

CONCLUSIONS

MCI extract from Turkish galls played protective effects on the X-ray induced damage through enhancing the scavenging activity of ROS, decreasing Bax/Bcl-2 ratio and the down-regulating the activity of procaspase-3, as well as modulating the mitogen-activated protein kinase (MAPK) signaling pathways.

Dynamics of preventive vs post-diagnostic cancer control using low-impact measures

Cancer poses danger because of its unregulated growth, development of resistance, and metastatic spread to vital organs. We currently lack quantitative theory for how preventive measures and post-diagnostic interventions are predicted to affect risks of a life threatening cancer. Here we evaluate how continuous measures, such as life style changes and traditional treatments, affect both neoplastic growth and the frequency of resistant clones. We then compare and contrast preventive and post-diagnostic interventions assuming that only a single lesion progresses to invasive carcinoma during the life of an individual, and resection either leaves residual cells or metastases are undetected. Whereas prevention generally results in more positive therapeutic outcomes than post-diagnostic interventions, this advantage is substantially lowered should prevention initially fail to arrest tumour growth. We discuss these results and other important mitigating factors that should be taken into consideration in a comparative understanding of preventive and post-diagnostic interventions.

DOI:http://dx.doi.org/10.7554/eLife.06266.001

About one person in every two will get cancer during their lives. Surgery and chemotherapy have long been mainstays of cancer treatment. Both, however, have substantial downsides. Surgery may leave behind undetected cancer cells that can grow into new tumours. Furthermore, in response to chemotherapy drugs, some cancer cells may emerge that resist further treatment. There is therefore interest in whether preventive strategies—including lifestyle changes and medications—could reduce the likelihood of confronting a life-threatening cancer.

Now, Akhmetzhanov and Hochberg have developed a mathematical model to help compare the effectiveness of preventive strategies and traditional cancer treatments. The model—which assumes that a person can only develop a single cancer from a single region of pre-cancerous cells—suggests that long-term cancer prevention strategies reduce the risk of a life-threatening cancer by more than traditional treatment that begins after a tumour is discovered. The preventive measures may be less effective in some cases compared to traditional treatments if they initially fail to stop a tumour growing, although on average they still work better than treating the cancer after detection.

According to Akhmetzhanov and Hochberg's model, surgical removal followed by chemotherapy is less likely to be successful than prevention, and when successful, requires larger impacts on the cancer (and therefore creates more side-effects for the patient) to achieve the same level of control as prevention. The model also suggests that even at very low levels of impact on residual cancer cells, chemotherapies are likely to be counterproductive by boosting the subsequent emergence of treatment-resistant tumours.

Akhmetzhanov and Hochberg's model predicts how effective preventive measures need to be in terms of slowing the growth of cancer cells to result in given reductions in the future risk of a life-threatening cancer. Future work should test this model by measuring the effects on tumour growth of prevention and of traditional therapies.

DOI:http://dx.doi.org/10.7554/eLife.06266.002

Risk-optimized proton therapy to minimize radiogenic second cancers

Proton therapy confers substantially lower predicted risk of second cancer compared with photon therapy. However, no previous studies have used an algorithmic approach to optimize beam angle or fluence-modulation for proton therapy to minimize those risks. The objectives of this study were to demonstrate the feasibility of risk-optimized proton therapy and to determine the combination of beam angles and fluence weights that minimizes the risk of second cancer in the bladder and rectum for a prostate cancer patient. We used 6 risk models to predict excess relative risk of second cancer. Treatment planning utilized a combination of a commercial treatment planning system and an in-house risk-optimization algorithm. When normal-tissue dose constraints were incorporated in treatment planning, the risk model that incorporated the effects of fractionation, initiation, inactivation, repopulation and promotion selected a combination of anterior and lateral beams, which lowered the relative risk by 21% for the bladder and 30% for the rectum compared to the lateral-opposed beam arrangement. Other results were found for other risk models.

Complications after radical prostatectomy or radiotherapy for prostate cancer: results of a population-based, propensity score-matched analysis

OBJECTIVE

To assess rates of treatment-related complications after radical prostatectomy or radiotherapy monotherapy, using propensity score matching to account for baseline differences between these patient populations.

METHODS

On the basis of a population-based study of men undergoing surgery or radiotherapy for prostate cancer in Ontario between 2002 and 2009, we undertook a propensity score-matched analysis including age, comorbidity, and year of treatment to assess treatment-related complication end points. These included hospital admission; urologic, rectal, or anal procedures; open surgeries; and secondary malignancies.

RESULTS

From the original cohort of 32,465 patients, 15,870 (48.9%) had surgery and 16,595 (51.1%) had radiation. Propensity score matching produced 8797 pairs (17,594 patients). Among these, when compared with patients treated with surgery, those treated with radiation experienced fewer admissions to hospital (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.78-0.92) and urologic procedures (HR, 0.50; 95% CI, 0.46-0.53) at year 1 but higher rates at year 3 (HR, 5.65; 95% CI, 4.61-6.91 and HR, 1.86; 95% CI, 1.62-2.13, respectively) and year 5. Although there was no significant difference in open surgeries at year 1, patients undergoing radiotherapy were at higher risk by year 3 (HR, 2.06; 95% CI, 1.23-3.47) and this rose by year 5. Over the study period, patients undergoing radiotherapy experienced more rectal-anal procedures (HR, 2.64; 95% CI, 2.37-2.95) and were diagnosed with more secondary malignancies (HR, 2.44; 95% CI, 1.16-5.14). Direct matching produced similar results.

CONCLUSION

From a propensity score-matched analysis, we found that patients undergoing radiation therapy for prostate cancer had higher rates of long-term complications in all 5 categories studied than patients undergoing surgery.

Benefits, risks, and safety of external beam radiation therapy for breast cancer

Breast cancer is a common and complex disease often necessitating multimodality care. Breast cancer may be treated with surgical resection, radiotherapy (RT), and systemic therapy, including chemotherapy, hormonal therapy, and targeted therapies, or a combination thereof. In the past 50 years, RT has played an increasingly significant role in the treatment of breast cancer, resulting in improvements in locoregional control and survival for women undergoing mastectomy who are at high risk of recurrence, and allowing for breast conservation in certain settings. Although radiation provides significant benefit to many women with breast cancer, it is also associated with risks of toxicity, including cardiac and pulmonary toxicity, lymphedema, and secondary malignancy. RT techniques have advanced and continue to evolve dramatically, offering increased precision and reproducibility of treatment delivery and flexibility of treatment schedule. This increased sophistication of RT offers promise of improved outcomes by maintaining or improving efficacy, reducing toxicity, and increasing patient access and convenience. A review of the role of radiation therapy in breast cancer, its associated toxicities and efforts in toxicity reduction is presented.

[Current situation and perspectives of proton therapy]

Proton beam therapy is indicated as a treatment for some rare tumours and paediatric tumours because the technique allows a good local control with minimal toxicity; the growing number of centres that use proton beam therapy is associated with an increase of dosimetric and clinical data for other malignant tumours as well. This paper reviews potential indications of proton beam therapy. A systematic review on Medline was performed with the following keywords proton beam therapy, cancer, heavy particle, charged particle. No phase III trial has been published using proton beam therapy in comparison with the best photon therapy, but numerous retrospective and dosimetric studies have revealed an advantage of proton beam therapy compared to photons, above all in tumours next to parallel organs at risk (thoracic and abdominal tumours). This could be accompanied with a better safety profile and/or a better tumoural control; numerous phase 0, I, II, III and IV studies are ongoing to examine these hypotheses in more common cancers. Use of proton beam therapy is growing for common cancers within clinical trials but some indications could be applied sooner since in silico analysis showed major advantages with this technique.

New cancers after autotransplantations for multiple myeloma

We describe baseline incidence and risk factors for new cancers in 4161 persons receiving autotransplants for multiple myeloma in the United States from 1990 to 2010. Observed incidence of invasive new cancers was compared with expected incidence relative to the US population. The cohort represented 13,387 person-years at-risk. In total, 163 new cancers were observed, for a crude incidence rate of 1.2 new cancers per 100 person-years and cumulative incidences of 2.6% (95% confidence interval [CI], 2.09 to 3.17), 4.2% (95% CI, 3.49 to 5.00), and 6.1% (95% CI, 5.08 to 7.24) at 3, 5, and 7 years, respectively. The incidence of new cancers in the autotransplantation cohort was similar to age-, race-, and gender-adjusted comparison subjects with an observed/expected (O/E) ratio of 1.00 (99% CI, .81 to 1.22). However, acute myeloid leukemia and melanoma were observed at higher than expected rates with O/E ratios of 5.19 (99% CI, 1.67 to 12.04; P = .0004), and 3.58 (99% CI, 1.82 to 6.29; P < .0001), respectively. Obesity, older age, and male gender were associated with increased risks of new cancers in multivariate analyses. This large data set provides a baseline for comparison and defines the histologic type specific risk for new cancers in patients with MM receiving postautotransplantation therapies, such as maintenance.

Differential cross sections for electron-impact vibrational-excitation of tetrahydrofuran at intermediate impact energies

We report differential cross sections (DCSs) for electron-impact vibrational-excitation of tetrahydrofuran, at intermediate incident electron energies (15-50 eV) and over the 10°-90° scattered electron angular range. These measurements extend the available DCS data for vibrational excitation for this species, which have previously been obtained at lower incident electron energies (≤20 eV). Where possible, our data are compared to the earlier measurements in the overlapping energy ranges. Here, quite good agreement was generally observed where the measurements overlapped.

Complications following surgery with or without radiotherapy or radiotherapy alone for prostate cancer

BACKGROUND

Men undergoing treatment of clinically localised prostate cancer may experience a number of treatment-related complications, which affect their quality of life.

METHODS

On the basis of population-based retrospective cohort of men undergoing surgery, with or without subsequent radiotherapy, or radiotherapy alone for prostate cancer in Ontario, Canada, we measured the incidence of treatment-related complications using administrative and billing data.

RESULTS

Of 36 984 patients, 15 870 (42.9%) underwent surgery alone, 4519 (12.2%) underwent surgery followed by radiotherapy, and 16 595 (44.9%) underwent radiotherapy alone. For all end points except urologic procedures, the 5-year cumulative incidence rates were lowest in the surgery only group and highest in the radiotherapy only group. Intermediary rates were seen in the surgery followed by radiotherapy group, except for urologic procedures where rates were the highest in this group. Although age and comorbidity were important predictors, radiotherapy as the primary treatment modality was associated with higher rates for all complications (adjusted hazard ratios 1.6-4.7, P=0.002 to <0.0001).

CONCLUSIONS

In patients treated for prostate cancer, radiation after surgery increases the rate of complications compared with surgery alone, though these rates remain lower than patients treated with radiation alone. This information may inform patient and physician decision making in the treatment of prostate cancer.

Radiation-Associated Undifferentiated Pleomorphic Sarcoma is Associated with Worse Clinical Outcomes than Sporadic Lesions

BACKGROUND

Radiation therapy is used increasingly as a component of multidisciplinary treatment for many solid tumors. One complication of such treatment is the development of radiation-associated sarcoma (RAS). Undifferentiated pleomorphic sarcoma (UPS), previously termed "malignant fibrous histiocytoma" (MFH) is the most common histologic subtype of RAS. This study investigated the clinical outcomes for patients with radiation-associated UPS (RA-UPS/MFH).

METHODS

The study identified 1068 patients with UPS/MFH treated at the authors' institution. Patient and tumor factors were collected and compared. Regression analysis was performed to identify independent predictors of survival. A matched-cohort survival and recurrence analysis was performed for radiation-associated and sporadic UPS/MFH.

RESULTS

The findings showed that RA-UPS/MFH comprised 5.1 % of the UPS population. The median latency to the development of RA-UPS/MFH was 9.3 years. The 5-year disease-specific survival (DSS) was 52.2 % for patients identified with RA-UPS/MFH (n = 55) compared with 76.4 % for patients with unmatched sporadic UPS/MFH (n = 1,013; p < 0.001). A matched-cohort analysis also demonstrated that the 5-year DSS was significantly worse for RA-UPS/MFH (52.2 vs 73.4 %; p = 0.002). Furthermore, higher local recurrence rates were observed for patients with RA-UPS/MFH than for patients with sporadic lesions (54.5 vs 23.5 %; p < 0.001). Radiation-associated status and incomplete resection were identified as independent predictors of local recurrence.

CONCLUSION

This study demonstrated worse clinical outcomes for patients with RA-UPS/MFH than for patients with sporadic UPS/MFH. Local recurrence was significantly higher for patients with RA-UPS/MFH, suggesting a unique tumor biology for this challenging disease.

Early toxicity in patients treated with postoperative proton therapy for locally advanced breast cancer

PURPOSE

To report dosimetry and early toxicity data in breast cancer patients treated with postoperative proton radiation therapy.

METHODS AND MATERIALS

From March 2013 to April 2014, 30 patients with nonmetastatic breast cancer and no history of prior radiation were treated with proton therapy at a single proton center. Patient characteristics and dosimetry were obtained through chart review. Patients were seen weekly while on treatment, at 1 month after radiation therapy completion, and at 3- to 6-month intervals thereafter. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Frequencies of toxicities were tabulated.

RESULTS

Median dose delivered was 50.4 Gy (relative biological equivalent [RBE]) in 5 weeks. Target volumes included the breast/chest wall and regional lymph nodes including the internal mammary lymph nodes (in 93%). No patients required a treatment break. Among patients with >3 months of follow-up (n=28), grade 2 dermatitis occurred in 20 patients (71.4%), with 8 (28.6%) experiencing moist desquamation. Grade 2 esophagitis occurred in 8 patients (28.6%). Grade 3 reconstructive complications occurred in 1 patient. The median planning target volume V95 was 96.43% (range, 79.39%-99.60%). The median mean heart dose was 0.88 Gy (RBE) [range, 0.01-3.20 Gy (RBE)] for all patients, and 1.00 Gy (RBE) among patients with left-sided tumors. The median V20 of the ipsilateral lung was 16.50% (range, 6.1%-30.3%). The median contralateral lung V5 was 0.34% (range, 0%-5.30%). The median maximal point dose to the esophagus was 45.65 Gy (RBE) [range, 0-65.4 Gy (RBE)]. The median contralateral breast mean dose was 0.29 Gy (RBE) [range, 0.03-3.50 Gy (RBE)].

CONCLUSIONS

Postoperative proton therapy is well tolerated, with acceptable rates of skin toxicity. Proton therapy favorably spares normal tissue without compromising target coverage. Further follow-up is necessary to assess for clinical outcomes and cardiopulmonary toxicities.

Incidence of subsequent cholangiocarcinomas after another malignancy: trends in a population-based study

Cholangiocarcinoma (CCA) characterized by late diagnosis and poor outcomes represents the commonest malignancy of biliary tract. Understanding metachronous cancer associations may achieve earlier detection. We aimed to evaluate the risk of subsequent CCAs among common cancer survivors. The National Cancer Institute's Surveillance, Epidemiology, and End Results database (1973-2010) was reviewed for patients with 1 of the 25 primary cancers. Standardized incidence ratios (SIRs) were calculated as an approximation of relative risk for subsequent CCAs after primary malignancy. Data were stratified by age at primary cancer diagnosis, latency period, and application of radiation. A total of 1487 patients developed subsequent CCAs. For patients diagnosed with primary cancers between the ages 20 and 39 years, the risk was increased among colon (SIR 14.65), gallbladder (129.29), and uterus (7.29) cancer survivors. At ages of 40 to 59 years, oral cavity and pharynx (1.89), stomach (3.24), colon (1.76), gallbladder (11.78), and lung cancers (1.75) were associated with increased risk. We found persistently elevated SIRs after colon and gallbladder cancer between ages 60 and 79 years. The SIR remained significant among gallbladder cancer survivors diagnosed after 80 years. Gallbladder cancer showed elevated risk at all of the latency periods except first 6 to 11 months. Increased risk of lung cancer (1.66) was detected after 120 months. However, radiation therapy did not contribute to increased risk. This population-based study suggests that several initial cancers are associated with elevated risk of CCA. The increased risk may be due to shared genetic or environmental etiological factors between these malignancies. Lower threshold for CCA surveillance may be warranted in high-risk patients.

Management of older women with early-stage breast cancer

Breast cancer is a disease of aging. The average age at diagnosis is 61, and the majority of deaths occur after age 65. Caring for older women with breast cancer is a major challenge, as many have coexisting illness that can preclude optimal breast cancer treatment and which frequently have greater effect than the breast cancer itself. Older patients with cancer should be screened or have a brief geriatric assessment to detect potentially remediable problems not usually assessed by oncologists (e.g., self-care, falls, social support, nutrition). Older women with early-stage breast cancer should be treated initially with surgery unless they have an exceedingly short life expectancy. Primary endocrine therapy should be considered for patients who have hormone receptor-positive tumors and a very short life expectancy, an acute illness that delays surgery, or tumors that need to be downstaged to be resectable. Sentinel node biopsy should be considered for patients in whom it might affect treatment decisions. Breast irradiation after breast-conserving surgery may be omitted for selected older women, especially for those with hormone receptor-positive early-stage breast cancer that are compliant with adjuvant endocrine therapy. The majority of older women with stage I and II breast cancer have hormone receptor-positive, HER2-negative tumors, and endocrine therapy provides them with optimal systemic treatment. If these patients have life expectancies exceeding at least 5 years, they should be considered for genetic assays to determine the potential value of chemotherapy. Partnering care with geriatricians or primary care physicians trained in geriatrics should be considered for all vulnerable and frail older patients.

No Increased Risk of Second Cancer After Radiotherapy in Patients Treated for Rectal or Endometrial Cancer in the Randomized TME, PORTEC-1, and PORTEC-2 Trials

PURPOSE

This study investigated the long-term probability of developing a second cancer in a large pooled cohort of patients treated with surgery with or without radiotherapy (RT).

PATIENTS AND METHODS

All second cancers diagnosed in patients included in the TME, PORTEC-1, and PORTEC-2 trials were analyzed. In the TME trial, patients with rectal cancer (n = 1,530) were randomly allocated to preoperative external-beam RT (EBRT; 25 Gy in five fractions) or no RT. In the PORTEC trials, patients with endometrial cancer were randomly assigned to postoperative EBRT (46 Gy in 2-Gy fractions) versus no RT (PORTEC-1; n = 714) or EBRT versus vaginal brachytherapy (VBT; PORTEC-2; n = 427).

RESULTS

A total of 2,554 patients were analyzed (median follow-up, 13.0 years; range 1.8 to 21.2 years). No differences were found in second cancer probability between patients who were treated without RT (10- and 15-year rates, 15.8% and 26.5%, respectively) and those treated with EBRT (10- and 15-year rates, 15.4% and 25.6%, respectively) or VBT (10-year rate, 14.9%). In the individual trials, no significant differences were found between treatment arms. All cancer survivors had a higher risk of developing a second cancer compared with an age- and sex-matched general population. The standardized incidence ratio for any second cancer was 2.98 (95% CI, 2.82 to 3.14).

CONCLUSION

In this pooled trial cohort of > 2,500 patients with pelvic cancers, those who underwent EBRT or VBT had no higher probability of developing a second cancer than patients who were treated with surgery alone. However, patients with rectal or endometrial cancer had an increased probability of developing a second cancer compared with the general population.

Trial Watch: Radioimmunotherapy for oncological indications

During the past two decades, it has become increasingly clear that the antineoplastic effects of radiation therapy do not simply reflect the ability of X-, β- and γ-rays to damage transformed cells and directly cause their permanent proliferative arrest or demise, but also involve cancer cell-extrinsic mechanisms. Indeed, among other activities, radiotherapy has been shown to favor the establishment of tumor-specific immune responses that operate systemically, underpinning the so-called 'out-of-field' or 'abscopal' effect. Thus, ionizing rays appear to elicit immunogenic cell death, a functionally peculiar variant of apoptosis associated with the emission of a particularly immunostimulatory combination of damage-associated molecular patterns. In line with this notion, radiation therapy fosters, and thus exacerbates, the antineoplastic effects of various treatment modalities, including surgery, chemotherapy and various immunotherapeutic agents. Here, we summarize recent advances in the use of ionizing rays as a means to induce or potentiate therapeutically relevant anticancer immune responses. In addition, we present clinical trials initiated during the past 12 months to test the actual benefit of radioimmunotherapy in cancer patients.

Body mass index and risk of second obesity-associated cancers after colorectal cancer: a pooled analysis of prospective cohort studies

PURPOSE

To determine whether prediagnostic body mass index (BMI) is associated with risk of second obesity-associated cancers in colorectal cancer (CRC) survivors, and whether CRC survivors have increased susceptibility to obesity-associated cancer compared with cancer-free individuals.

PATIENTS AND METHODS

Incident first primary CRC cases (N = 11,598) were identified from five prospective cohort studies. We used Cox proportional hazards regression models to examine associations between baseline (prediagnostic) BMI and risk of second obesity-associated cancers (postmenopausal breast, kidney, pancreas, esophageal adenocarcinoma, endometrium) in CRC survivors, and compared associations to those for first obesity-associated cancers in the full cohort.

RESULTS

Compared with survivors with normal prediagnostic BMI (18.5-24.9 kg/m(2)), those who were overweight (25-29.9 kg/m(2)) or obese (30+ kg/m(2)) had greater risk of a second obesity-associated cancer (n = 224; overweight hazard ratio [HR], 1.39; 95% CI, 1.01 to 1.92; obese HR, 1.47; 95% CI, 1.02 to 2.12; per 5-unit change in BMI HR, 1.12; 95% CI, 0.98 to 1.29). The magnitude of risk for developing a first primary obesity-associated cancer was similar (overweight HR, 1.18; 95% CI, 1.14 to 1.21; obese HR, 1.61; 95% CI, 1.56 to 1.66; per 5-unit change in BMI HR, 1.23; 95% CI, 1.21 to 1.24). Before diagnosis CRC patients were somewhat more likely than the overall cohort to be overweight (44% v 41%) or obese (25% v 21%).

CONCLUSION

CRC survivors who were overweight or obese before diagnosis had increased risk of second obesity-associated cancers compared with survivors with normal weight. The risks were similar in magnitude to those observed for first cancers in this population, suggesting increased prevalence of overweight or obesity, rather than increased susceptibility, may contribute to elevated second cancer risks in colorectal cancer survivors compared with the general population. These results support emphasis of existing weight guidelines for this high-risk group.

Pooling prospective studies to investigate the etiology of second cancers

BACKGROUND

With over 13 million cancer survivors in the United States today, second cancers are of rapidly growing importance. However, data on nontreatment risk factors for second cancers are sparse. We explored the feasibility of pooling data from cohort studies of cancer incidence to investigate second cancer etiology.

METHODS

We combined data from five prospective studies including more than 800,000 individuals. We compared study designs and populations; evaluated availability of and ability to harmonize risk factor data; compared incidence and survival for common first primary malignancies and incidence of second primary malignancies; and estimated sample size requirements.

RESULTS

Overall, 96,513 incident, first primary malignancies were diagnosed during 1985 to 2009. Incidence rates and survival following the first primary varied among the cohorts, but most of the heterogeneity could be explained by characteristics of the study populations (age, sex, smoking, and screening rates). A total of 7,890 second primary cancers (excluding original primary site) were identified, yielding sufficient statistical power (≥80%) for detecting modest associations with risk of all second cancers among survivors of common first primary malignancies (e.g., colorectal cancer); however, there were insufficient events for studying survivors of rarer cancers or identifying risk factors for specific second cancers.

CONCLUSIONS

Pooling data from cohort studies to investigate nontreatment risk factors for second primary cancers seems feasible but there are important methodologic issues-some of which are barriers to specific research questions-that require special attention.

IMPACT

Increased understanding of nontreatment risk factors for second cancers will provide valuable prevention and surveillance information.

Risk of colorectal cancer among long-term cervical cancer survivors

Because advances in therapy have increased long-term survival for women with cervical cancer, it is important to study the risk of secondary primary malignancies in high-dose organ areas. From the 1973-2009 National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program, we studied the risk of developing cancer of the colon and rectum in 64,507 cervical cancer patients over 35 years after initial radiation treatment. We also assessed change in risk over time. Kaplan-Meier estimator for survival curve and Cox proportional hazards models was used. More than half (52.6%) of the cervical cancer patients received radiation treatment. In the analyses adjusted for race/ethnicity, age, marital status, surgery status, stage and grade, the risk of colon cancer between those both with and without XRT diverged beginning at approximately 8 years. After 8 years, the hazard ratio for developing colon cancer was 2.00 (95% CI 1.43-2.80) for women with radiation versus those without radiation treatment. The risk of rectal cancer diverged after 15 years of follow-up (HR 4.04, 95% CI 2.08-7.86). After 35 years of follow-up, the absolute risk of developing colon cancer was 6.5% for those who received radiation versus 2.5% for those without, and 3.7 versus 0.8% for rectum. The risk of colon and rectum cancer over 20 years of follow-up after radiation remained the same across three eras (1973-1980, 1981-1990, and 1991-2000). Radiation-induced second cancers of the colon and rectum may occur 8 years after radiation treatment for cervical cancer.

Secondary malignant neoplasms following radiotherapy for primary cancer in children and young adults

A study was conducted to investigate secondary malignant neoplasm (SMN) occurrence following radiotherapy (RT) for cancer in children and young adults, to examine the spatial distribution of SMNs in relation to the irradiated field, and to evaluate a possible role of bystander effects in SMN distribution. Forty-two SMNs were identified among 7257 subjects diagnosed with cancer while living in Yorkshire, UK. Thirty-two of these occurred in patients receiving RT. Distances between SMN locations and RT field edge were estimated along with dose at SMN site. Expected radiation-induced SMN frequency in remote tissues receiving less than 0.1 Gy was predicted using risk estimates based on atomic bombing data. After a median follow-up period of 7.58 years, patients treated with RT were at a nearly five-fold increased risk of developing a subsequent primary neoplasm than the general population in the 0-29 years age range. The most common type of secondary malignancy associated with RT was of the central nervous system (28%), followed by sarcoma (25%) and leukemia (19%). Considering only solid SMNs developing 5 years or more from treatment, the spatial distribution showed a strong pattern of proximity to the irradiated field, with 68% occurring in-field or within 8 cm of the field edge. The SMN frequency in distant tissues receiving doses of less than 0.1 Gy was low but compatible with local absorbed dose.

Risk of second benign brain tumors among cancer survivors in the surveillance, epidemiology, and end results program

PURPOSE

To assess risk of developing a second benign brain tumor in a nationwide population of cancer survivors.

METHODS

We evaluated the risk of developing second benign brain tumors among 2,038,074 1-year minimum cancer survivors compared to expected risk in the general population between 1973 and 2007 in nine population-based cancer registries in the NCI's surveillance, epidemiology, and end results program. Excess risk was estimated using standardized incidence ratios (SIRs) for all second benign brain tumors and specifically for second meningiomas and acoustic neuromas diagnosed during 2004-2008.

RESULTS

1,025 patients were diagnosed with a second primary benign brain tumor, of which second meningiomas composed the majority (n = 745). Statistically significant increases in risk of developing a second meningioma compared to the general population were observed following first cancers of the brain [SIR = 19.82; 95 % confidence interval (CI) 13.88-27.44], other central nervous system (CNS) (SIR = 9.54; CI 3.10-22.27), thyroid (SIR = 2.05; CI 1.47-2.79), prostate (SIR = 1.21; CI 1.02-1.43), and acute lymphocytic leukemia (ALL) (SIR = 42.4; CI 23.18-71.13). Statistically significant decreases in risk were observed following first cancers of the uterine corpus (SIR = 0.63; CI 0.42-0.91) and colon (SIR = 0.56; CI 0.37-0.82). Differences in risk between patients initially treated with radiotherapy versus non-irradiated patients were statistically significant for second meningioma after primary cancers of the brain (p Het < 0.001) and ALL (p Het = 0.02). No statistically significant increased risks were detected for second acoustic neuromas (n = 114) following any first primary tumor.

CONCLUSIONS

Risk of second benign brain tumors, particularly meningioma, is increased following first primary cancers of the brain/CNS, thyroid, prostate, and ALL. Radiation exposure likely contributes to these excess risks.

Risk for developing myelodysplastic syndromes in prostate cancer patients definitively treated with radiation

BACKGROUND

Exposure to ionizing radiation has been linked to myelodysplastic syndromes (MDS); it is not clear whether therapeutic radiation doses used for prostate cancer pose an increased MDS risk.

METHODS

We performed a retrospective cohort study of prostate cancer patients diagnosed between 1986 and 2011 at Cleveland Clinic, comparing those who underwent definitive treatment with radical prostatectomy (RP) to radiotherapy either external beam radiotherapy (EBRT) or prostate interstitial brachytherapy (PI) and to population-based registries. Competing risk regression analyses were used to determine the cumulative risk of developing MDS. All statistical tests were two-sided.

RESULTS

Of 10924 patients, 5119 (47%) received radiation (n = 2183 [43%] in EBRT group and n = 2936 [57%] in PI group) and 5805 (53%) were treated with RP. Overall, 31 cases of MDS were observed, with age-adjusted incidence rates no higher than in population-based registries. In univariate analyses, advancing age (hazard ratio [HR] = 1.14; 95% confidence interval [CI] = 1.09 to 1.20; P < .001) and radiotherapy exposure (HR = 3.44; 95% CI = 1.41 to 8.37; P = .007) were statistically significantly associated with development of MDS. In multivariable analyses, although advanced age (HR = 1.13; 95% CI = 1.06 to 1.19; P < .001) remained statistically associated with MDS, radiation did not, although a small non-statistically significant trend existed for PI-treated patients. MDS rates were no higher than in population-based registries.

CONCLUSIONS

With relatively short follow-up, prostate cancer patients definitively treated with radiation did not appear to have a statistically increased risk of subsequent MDS.

[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.

The effect of patient characteristics on second primary cancer risk in France

Background

Although cancer survivors are known to be at greater risk of developing second primary cancer (SPC), SPC incidence estimates in France are thus far lacking. We used a multivariate approach to compute these estimates and analyzed the effect of patient characteristics (gender, age at diagnosis, first cancer site, year of diagnosis and follow-up) on SPC risk.

Methods

Data from ten French population-based cancer registries were used to establish a cohort of all patients diagnosed with a first cancer between 1989 and 2004 and followed up until December 31, 2007. The person-year approach was used to estimate standardized incidence ratios (SIRs) and excess absolute risks (EARs) of metachronous SPC. Multivariate Poisson regression models were then used to model SIRs and EARs separately by gender, adjusting for age, year of diagnosis, follow-up and first cancer site.

Results

Among the 289,967 followed-up patients with a first primary cancer, 21,226 developed a SPC. The SIR was of 1.36 (95% CI, 1.35-1.38) and the EAR was of 39.4 excess cancers per 10,000 person-years (95% CI, 37.4-41.3). Among male and female patients, multivariate analyses showed that age, year of diagnosis, follow-up and first cancer site were often independently associated with SIRs and EARs. Moreover, the EAR of SPC remained elevated during patient follow-up.

Conclusions

French cancer survivors face a dramatically increased risk of SPC which is probably related to the high rate of tobacco and alcohol consumption in France. Multivariate modeling of SPC risk will facilitate the construction of a tailored prediction tool to optimize SPC prevention and early detection strategies.

Solid tumor second primary neoplasms: who is at risk, what can we do?

Eighteen percent of incident malignancies in the United States are a second (or subsequent) cancer. Second primary neoplasms (SPNs), particularly solid tumors, are a major cause of mortality and serious morbidity among cancer survivors successfully cured of their first cancer. Multiple etiologies may lead to a cancer survivor subsequently being diagnosed with an SPN, including radiotherapy for the first cancer, unhealthy lifestyle behaviors, genetic factors, aging, or an interaction between any of these factors. In this article, we discuss these factors and synthesize this information for use in clinical practice, including preventive strategies and screening recommendations for SPNs.

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.

A novel approach for superficial intraoperative radiotherapy (IORT) using a 50 kV X-ray source: a technical and case report

The use of IORT as a treatment modality for patients with close or positive margins has increased over the past decade. For situations where a flat area (up to 6 cm in diameter) has to be treated intraoperatively, new applicators for superficial treatment with a miniature X‐ray source (INTRABEAM system) were developed. Here we report our evaluation of the dosimetric characteristics of these new applicators and their first clinical use. Each of these flat and surface applicators consists of a radiation protective metal tube and a flattening filter, which converts the spherical dose distribution of the X‐ray source into a flat one. The homogeneity of each dose distribution and depth‐dose measurements were evaluated using film dosimetry in a solid water phantom and a soft X‐ray ionization chamber in a water tank. The first patient was treated with 5 Gy delivered in 5 mm using a 4 cm FLAT applicator over 21 minutes. The flat applicators show the maximum homogeneity, with a uniformity ratio of 1.02‐1.08 in certain depths. In 1 mm depth surface applicators show a uniformity ratio of 1.15‐1.28. They also show a higher dose rate and a steeper dose gradient compared to the flat applicators. The results of this investigation demonstrated that the flat and surface applicators have unique dosimetric characteristics that need to be considered during the treatment planning stages. This work also showed that it is possible to perform a superficial localized IORT which provides new application possibilities for use of the INTRABEAM system.

PACS number: 87.55.ne

Prognostic factors and survival in patients with radiation-related second malignant neoplasms following radiotherapy for nasopharyngeal carcinoma

Purpose

To analyze the clinicopathological characteristics, treatment modalities, and potential prognostic factors of radiation-related second malignant neoplasms (SMNs) in a large group of nasopharyngeal carcinoma (NPC) cases.

Methods and Materials

Institutional electronic medical records of 39,118 patients with NPC treated by definitive radiotherapy between February 1964 and December 2003 were reviewed. A total of 247 patients with confirmed SMN attributable to radiotherapy were included.

Results

Median latency between radiotherapy for NPC and the diagnosis of SMN was 9.5 years (range, 3.1–36.8 years). Squamous cell carcinoma was the most common histologic type, followed by fibrosarcoma and adenocarcinoma. Median progression-free survival and overall survival (OS) of the 235 patients who underwent treatment were 17.3 months and 28.5 months, respectively. The 5-year OS rates were 42.9%, 23.7%, and 0% for the surgery, radiotherapy, and chemotherapy groups, respectively. The independent prognostic factors associated with survival were sex, histologic type, and treatment modality in both the early stage subgroup and the advanced stage subgroup of SMN.

Conclusions

Sex, histologic type, and treatment modality were the significant prognostic factors for SMN. Complete resection offers the best chance for long-term survival. In select patients with locally advanced and unresectable SMN, reirradiation should be strongly considered as a curative option.

Preoperative intensity-modulated and image-guided radiotherapy with a simultaneous integrated boost in locally advanced rectal cancer: report on late toxicity and outcome

BACKGROUND AND PURPOSE

The addition of chemotherapy to preoperative radiotherapy has been established as the standard of care for patients with cT3-4 rectal cancer. As an alternative strategy, we explored intensity-modulated and image-guided radiotherapy (IMRT-IGRT) with a simultaneous integrated boost (SIB) in a prospective phase II study. Here, we report outcome and late toxicity after a median follow-up of 54 months.

METHODS AND MATERIALS

A total of 108 patients were treated preoperatively with IMRT-IGRT, delivering a dose of 46 Gy in fractions of 2 Gy. Patients (n=57) displaying an anticipated circumferential resection margin (CRM) of less than 2mm based on magnetic resonance imaging received a SIB to the tumor up to a total dose of 55.2 Gy.

RESULTS

The absolute incidence of grade ≥3 late gastrointestinal and urinary toxicity was 9% and 4%, respectively, with a 13% rate of any grade ≥3 late toxicity. The actuarial 5-year local control (LC), progression-free survival (PFS) and overall survival (OS) were 97%, 57%, and 68%. On multivariate analysis, R1 resection and pN2 disease were associated with significantly impaired OS.

CONCLUSIONS

The use of preoperative IMRT-IGRT with a SIB resulted in a high 5-year LC rate and non-negligible late toxicity.