Multiple primary tumors involving cancer of the brain and central nervous system as the first or subsequent cancer

Second primary malignancies after ocular adnexal lymphoma diagnosis

BACKGROUND

Although studies have investigated the risk of second primary malignancies (SPMs) associated with lymphoma of various sites, limited studies have investigated this risk in patients with lymphoma originating within the ocular adnexa. We conducted a retrospective study to assess incidence of secondary malignancies in patients with a prior diagnosis of ocular adnexal lymphoma (OAL) and to determine latency periods and age-groups at increased risk for SPM occurrence.

METHODS

Retrospective analysis was performed on data obtained from Surveillance, Epidemiology, and End Results (SEER) 9 database. Patients with an initial primary malignancy diagnosis of OAL between 1973 and 2015 were included in the study. Standardized incidence ratios (SIR) and excess absolute risks (EAR) compared to a SEER reference population with similar sex, race, age, and calendar year were computed for SPMs. Excess absolute risk is per 10,000 individuals; alpha of 0.05 was used.

RESULTS

Of 1834 patients with primary ocular adnexal lymphoma, 279 developed a secondary malignancy during average follow-up of 110.03 months (+/- 88.46), denoting higher incidence than expected (SIR 1.20; 95% CI, 1.07 to 1.35; EAR 30.56). Amongst the primary lymphoma cohort, 98.7% (1810/1834) of patients had non-Hodgkin's lymphoma and amongst those that developed secondary malignancies, 99.6% (278/279) had non-Hodgkin's lymphoma. Patients exhibited increased incidence of lymphohematopoietic and non-lymphohematopoietic second malignancies and no secondary malignancies of the eye or orbit. Patients had increased incidence of secondary malignancies in the first year (SIR 2.07; 95% CI, 1.49 to 2.79; EAR 150.37) and 1-5 years following lymphoma diagnosis (SIR 1.24; 95% CI, 1.01 to 1.51; EAR 34.89). Patients with various OAL subtypes demonstrated differing patterns of site-specific and overall SPM risk.

CONCLUSIONS

Patients with prior diagnosis of ocular adnexal lymphoma possess increased risk of hematologic and non-hematologic secondary malignancies. Risk of secondary malignancy could vary by lymphoma subtype. Patients with ocular adnexal lymphoma may benefit from regular surveillance to promote early detection of second primary malignancies.

Risk of subsequent cancer among pediatric, adult and elderly patients following a primary diagnosis of glioblastoma multiforme: a population-based study of the SEER database

Purpose/aim of the study: Our objective was to determine the risk of a subsequent malignancy in patients with glioblastoma multiforme (GBM).

MATERIALS AND METHODS

Data of patients with a primary diagnosis of GBM were extracted from the Surveillance, Epidemiology, and End Results database. Patients were divided into three age groups: pediatric, ≤19 years of age; adult, 20-59 years; elderly, ≥60 years. Outcomes were overall survival and incidence of second cancer.

RESULTS

A total of 24 348 patients with primary GBM were identified during the period from 2004 to 2013: 349 pediatric, 9841 adults and 14 518 elderly. There were significant differences in terms of sex, race, registry site, tumor histological type, tumor size and extension among the groups. The median survival time for pediatric, adult and elderly patients was 15, 15 and 5 months, respectively. Of the study population, 1.8% developed a second malignancy and the rates of the three groups were statistically different. Secondary tumors of the cranial nerves and other nervous system were the most common occurrence in the adults and elderly. Female, registry site, giant cell glioblastoma, undergoing surgery or radiation therapy were associated with developing a second malignancy.

CONCLUSIONS

The risk of a second malignancy in GBM patients is 1.8%, and associated with certain patient and treatment factors.

Second Primary Neoplasms in Patients With Uveal Melanoma: A SEER Database Analysis

PURPOSE

To determine the risk of second primary neoplasms (SPNs) in subjects previously diagnosed with uveal melanoma (UM), including an analysis on whether radiotherapy is a risk factor to develop these SPNs.

DESIGN

Retrospective cohort study.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) 9 database, we identified patients diagnosed with UM as their first malignancy between 1973 and 2011 (n = 3976). We obtained standardized incidence ratios (SIR) and excess absolute risks of SPNs on patients with UM compared to a reference population. Multivariate Cox regression models were used to evaluate the effect of radiotherapy in SPN risk.

RESULTS

Sixteen percent (n = 641) of the patients developed SPNs during a median follow-up of 83 months (range, 1-463 months). This represented an 11% excess risk compared to the reference population, mainly owing to a significantly increased risk of skin melanomas (SIR = 2.93, 95% CI: 2.23-3.78) and kidney tumors (SIR = 1.91, 95% CI: 1.27-2.76), primarily in those diagnosed between 30 and 59 years of age. The occurrence of second UM was also increased (SIR = 16.90, 95% CI: 9.00-28.90), which likely includes recurrences misclassified as a second cancer. Radiotherapy was performed in 39% (n = 1538) of the patients. Multivariate analysis revealed that this treatment was not an independent risk factor for SPNs (hazard ratio = 1.06, 95% CI: 0.88-1.26, P = .54).

CONCLUSIONS

Patients with UM presented an 11% higher risk of SPNs compared to the reference population. Radiotherapy does not seem to be a risk factor. SPNs should be considered in the surveillance of UM.

Multidisciplinary treatment based on surgery leading to long-term survival of a patient with multiple asynchronous rare primary malignant neoplasms: A case report and literature review

Patients that present with multiple primary malignant neoplasms are increasingly encountered, but the treatment of such patients presents specific challenges and long-term survival is rare. The present study reports the case of a 45-year-old female diagnosed with three rare, distinct primary malignant neoplasms, including epithelioid hemangioendothelioma (EHE) of the brain, Ewing’s sarcoma of the lumbar 2 vertebra and a malignant solitary fibrous tumour (SFT) of the liver, at different time points. The patient underwent multidisciplinary treatment according to the diagnoses, including radial resection of all primary lesions, chemotherapy (consisting of vincristine, dactinomycin, cyclophosphamide and adriamycin) and radiotherapy, to treat Ewing’s sarcoma and metastases of EHE and malignant SFT. Following these treatments, the patient survived for >14 years. Multidisciplinary treatment regimens based on surgery can lead to long-term survival of patients with multiple asynchronous rare primary malignant neoplasms. The present study reported that multidisciplinary treatment regimens based on surgery can lead to the long-term survival of patients with multiple asynchronous rare primary malignant neoplasms.

A recommendation for the management of lesions of unknown malignancy in multiple primary malignant neoplasm patients: A case report

In numerous patients with multiple primary malignant neoplasms, it is difficult to determine whether the mass is benign or malignant, and the method to treat these lesions is controversial. For patients with a history of cancer, a point of high-risk for the development of a second primary tumor occurs following a 10-year gap. To the best of our knowledge, to date, there has been no large clinical trial to observe the appropriate method to manage the lesions in patients with multiple primary malignant neoplasms. The present study reports the case of a patient who was initially diagnosed with rectal cancer, treated with Dixon’s rectectomy and post-operative chemotherapy. The patient’s disease was evaluated as complete response following these treatments. However, the patient then presented with bladder cancer and underwent transurethral resection of the bladder tumor, again achieving a complete response. The patient more recently presented with hepatocellular carcinoma, which developed from an unexplained mass in the liver. The patient underwent partial liver resection and to date, has achieved a complete response. The management of masses of unknown malignancy is also discussed. The current case provides useful insight for future research in this field.

Exploring the association between melanoma and glioma risks

PURPOSE

Gliomas are one of the most fatal malignancies, with largely unknown etiology. This study examines a possible connection between glioma and melanoma, which might provide insight into gliomas' etiology.

METHODS

Using data provided by the Surveillance, Epidemiology, and End Results program from 1992 to 2009, a cohort was constructed to determine the incidence rates of glioma among those who had a prior diagnosis of invasive melanoma. Glioma rates in those with prior melanoma were compared with those in the general population.

RESULTS

The incidence rate of all gliomas was greater among melanoma cases than in the general population: 10.46 versus 6.13 cases per 100,000 person-years, standardized incidence ratios = 1.42 (1.22-1.62). The female excess rate was slightly greater (42%) than that among males (29%). Sensitivity analyses did not reveal evidence that radiation treatment of melanoma is responsible for the detected gap in the rates of gliomas.

CONCLUSIONS

Our analysis documented increased risk of glioma among melanoma patients. Because no common environmental risk factors are identified for glioma and melanoma, it is hypothesized that a common genetic predisposition may be responsible for the detected association.

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 of subsequent cancer following a primary CNS tumor

Improvements in survival among central nervous system (CNS) tumor patients has made the risk of developing a subsequent cancer an important survivorship issue. Such a risk is likely influenced by histological and treatment differences between CNS tumors. De-identified data for 41,159 patients with a primary CNS tumor diagnosis from 9 Surveillance, Epidemiology and End Results (SEER) registries were used to calculate potential risk for subsequent cancer development. Relative risk (RR) and 95 % confidence interval (CI) of subsequent cancer was calculated using SEER*Stat 7.0.9, comparing observed number of subsequent cancers versus expected in the general United States population. For all CNS tumors studied, there were 830 subsequent cancers with a RR of 1.26 (95 % CI, 1.18-1.35). Subsequent cancers were observed in the CNS, digestive system, bones/joints, soft tissue, thyroid and leukemia. Radiotherapy was associated with an elevated risk, particularly in patients diagnosed with a medulloblastoma/primitive neuroectodermal tumor (MPNET). MPNET patients who received radiotherapy were at a significant risk for development of cancers of the digestive system, leukemia, bone/joint and cranial nerves. Glioblastoma multiforme patients who received radiotherapy were at lower risks for female breast and prostate cancers, though at an elevated risk for cancers of the thyroid and brain. Radiotherapy is associated with subsequent cancer development, particularly for sites within the field of radiation, though host susceptibility and post-treatment status underlie this risk. Variation in subsequent cancer risk among different CNS tumor histological subtypes indicate a complex interplay between risk factors in subsequent cancer development.

Risk of salivary gland cancer after childhood cancer: a report from the Childhood Cancer Survivor Study

PURPOSE

To evaluate effects of radiation therapy, chemotherapy, cigarette smoking, and alcohol consumption on the risk of second primary salivary gland cancer (SGC) in the Childhood Cancer Survivor Study (CCSS).

METHODS AND MATERIALS

Standardized incidence ratios (SIR) and excess absolute risks (EAR) of SGC in the CCSS were calculated using incidence rates from Surveillance, Epidemiology, and End Results population-based cancer registries. Radiation dose to the salivary glands was estimated based on medical records. Poisson regression was used to assess risks with respect to radiation dose, chemotherapy, smoking, and alcohol consumption.

RESULTS

During the time period of the study, 23 cases of SGC were diagnosed among 14,135 childhood cancer survivors. The mean age at diagnosis of the first primary cancer was 8.3 years, and the mean age at SGC diagnosis was 24.8 years. The incidence of SGC was 39-fold higher in the cohort than in the general population (SIR = 39.4; 95% CI = 25.4-57.8). The EAR was 9.8 per 100,000 person-years. Risk increased linearly with radiation dose (excess relative risk = 0.36/Gy; 95% CI = 0.06-2.5) and remained elevated after 20 years. There was no significant trend of increasing risk with increasing dose of chemotherapeutic agents, pack-years of cigarette smoking, or alcohol intake.

CONCLUSION

Although the cumulative incidence of SGC was low, childhood cancer survivors treated with radiation experienced significantly increased risk for at least 2 decades after exposure, and risk was positively associated with radiation dose. Results underscore the importance of long-term follow up of childhood cancer survivors for the development of new malignancies.

Eight primary malignancies: case report and review of literature

The incidence of multiple primary malignancies has increased over the past years secondary to the long-term survival of cancer patients due to improvements in the early detection and adequate treatment of cancer. We present a patient with eight primary malignant tumors and review the relevant literature. Our patient was a 59-year-old female with Crohn disease with an otherwise non-contributory medical history. Risk factors for multiple primary tumors were not detected in our patient. At a follow-up of 108 months from the time of diagnosis of the first malignancy, our patient was still alive. Similar long-term survival has been reported in the literature. Due to the realistic potential for long-term survival, we recommend aggressive treatment of these patients.

Multiple primary malignancies: analysis of 23 patients with at least three tumors

BACKGROUND

There is scarcity of reports addressing patients with three or more malignancies. The aim of this study is to present a detailed analysis of patients presenting with at least three primary malignant tumors.

PATIENTS AND METHODS

Records of cancer patients presenting to King Hussein Cancer Center (Amman, Jordan) between June 2006 and March 2011 were retrospectively reviewed. Patients harboring multiple primary tumors were included for detailed analysis. Data relating to epidemiological features, pathological characteristics, and disease outcomes were extracted.

RESULTS

Out of 14,040 cases, 319 patients (2.3%) harbored two or more while 23 patients (0.16%) harbored three or more primary malignant tumors. This study included 17 males and six females between 4 and 78 years of age (median, 52 years) at the time of diagnosis of the first malignancy. The most prevalent tumor was colorectal adenocarcinoma found in nine, followed by lymphoma in seven, and prostate adenocarcinoma in six patients. The most common tumor combinations were colorectum-non-melanoma skin, colorectum-kidney, and non-melanoma skin-kidney all found in four patients, respectively. At a median follow-up of 96 months from the time of diagnosis of the first primary (range, 2-337 months) and 8 months from the time of diagnosis of the last primary (range, 1-48 months), 13 were alive with no evidence of disease, six were alive with residual disease, three were dead due to disease, and one patient was alive with unknown disease status.

CONCLUSIONS

The possibility of multiple primary malignancies should always be considered during the treatment and follow-up of cancer patients. This case series could prove helpful to clinicians faced with similar, however, exceedingly rare scenarios. Due to the realistic potential for long-term survival, we recommend aggressive treatment of these patients.

Increased risk of second primary cancers after a diagnosis of melanoma

OBJECTIVE

To quantify the risk of subsequent primary cancers among patients with primary cutaneous malignant melanoma.

DESIGN

Population-based registry study.

SETTING

We evaluated data from 9 cancer registries of the Surveillance, Epidemiology, and End Results program from 1973-2006.

PARTICIPANTS

We included 89 515 patients who survived at least 2 months after their initial melanoma diagnosis.

RESULTS

Of the patients with melanoma, 10 857 (12.1%) developed 1 or more subsequent primary cancers. The overall risk of a subsequent primary cancer increased by 28% (observed to expected [O:E] ratio = 1.28). One quarter of the cancers were subsequent primary melanomas (O:E = 8.61). Women with head and neck melanoma and patients younger than 30 had markedly increased risks (O:E = 13.22 and 13.40, respectively) of developing a subsequent melanoma. Second melanomas were more likely to be thin than were the first of multiple primary melanomas (thickness at diagnosis <1.00 mm, 77.9% vs 70.3%, respectively; P < .001). Melanoma survivors had increased risk of developing several cancers; the most common cancers with elevated risks were breast, prostate, and non-Hodgkin lymphoma (O:E = 1.10, 1.15, and 1.25, respectively).

CONCLUSIONS

Melanoma survivors have an approximately 9-fold increased risk of developing subsequent melanoma compared with the general population. The risk remains elevated more than 20 years after the initial melanoma diagnosis. This increased risk may be owing to behavioral factors, genetic susceptibility, or medical surveillance. Although the percentage of subsequent primary melanomas thicker than 1 mm is lower than for the first of multiple primary melanomas, it is still substantial. Melanoma survivors should remain under surveillance not only for recurrence but also for future primary melanomas and other cancers.

[Epidemiology of primary brain tumor]

Two main approaches are generally used to study the epidemiology of primary brain tumors. The first approach is to identify risk factors, which may be intrinsic or related to external causes. The second main approach is descriptive. Intrinsic factors potentially affecting risk include genetic predisposition and susceptibility, gender, race, birth weight and allergy. Radiation exposure is the main extrinsic factor affecting risk. A large body of work devoted, among others, to electromagnetic fields and especially cellular phones, substitutive hormonal therapy, pesticides, and diet have been published. To date, results have been discordant. Descriptive epidemiological studies have reported an increasing annual incidence of primary brain tumors in industrialized countries. The main reasons are the increasing age of the population and better access to diagnostic imaging. Comparing incidences from one registry to another is difficult. Spatial and temporal variations constitute one explanation and evolutions in coding methods another. In all registries, weak incidence of primary brain tumors constitute a very important limiting factor. Renewed interest from the neuro-oncological community is needed to obtain pertinent and essential data which could facilitate improved knowledge on this topic.

Risk of radiation-related salivary gland carcinomas among survivors of Hodgkin lymphoma: a population-based analysis

BACKGROUND

Radiotherapy for Hodgkin lymphoma (HL) increases the risk of salivary gland carcinomas (SGC). To the authors' knowledge, however, the magnitude of the risk has not been assessed to date.

METHODS

The risks of SGC among 20,928 1-year survivors of HL who were diagnosed between 1973 and 2003 were evaluated in 11 population-based cancer registry areas of the Surveillance, Epidemiology, and End Results (SEER) program. Observed-to-expected ratios (O/E) were assessed by radiation treatment, sex, age at the time of HL diagnosis, calendar year of diagnosis, attained age, time since HL diagnosis, histologic type of SGC, and site of occurrence in the major salivary glands.

RESULTS

Among 11,047 HL patients who received radiotherapy as part of their initial treatment for HL, 21 developed subsequent invasive SGC (O/E = 16.9; 95% confidence interval [95% CI], 10.4-25.8). The risk of radiation-related SGC was highest for younger HL patients (age <20 years) (O/E = 45.5; 95% CI, 12.4-116.5) and among 10-year survivors (O/E = 23.9; 95% CI, 13.1-40.1), with risks remaining elevated for at least 2 decades after irradiation. Significant differences in risk by histologic type were observed, with a particularly high risk of developing mucoepidermoid carcinomas (O = 14; O/E = 44.2 [95% CI, 24.2-74.2]) and adenocarcinomas (O = 4; O/E = 30.6 [95% CI, 8.3-78.2]) noted.

CONCLUSIONS

HL patients treated with radiotherapy experienced a significantly increased risk of SGC, particularly when exposed at young ages or for at least 2 decades after exposure. Although the results of the current study reflect the late effects of former HL treatment approaches, they point to the importance of long-term follow-up and a heightened awareness of SGC risk in this population.

Second primary tumors following a diagnosis of meningioma in Sweden, 1958-1997

This study quantifies the risk of second primary tumors following a diagnosis of meningioma. 12,012 meningiomas and 926 second primary cancers were identified (ICD7, path code 461) between 1958 and 1997 using Swedish Cancer Registry data. Standardized incidence ratios (SIRs) and exact 95% confidence intervals (CIs) were calculated. An elevated risk of any second primary cancer diagnosis (SIR = 1.2, 95% CI = 1.1-1.3) was observed. Elevated and statistically significant SIRs were observed for renal cancer (SIR = 1.6), melanoma (SIR = 1.7), thyroid cancer (SIR = 2.6) and brain tumors (SIR = 2.6). A consistent pattern of risk over time supports the evaluation of common risk factor profiles for renal, melanoma and thyroid cancers. Radiation exposures increase the risk of these rare tumors, so quantifying the cumulative and shared effects of environmental and treatment exposures is of further interest.

Excess risk of subsequent primary cancers among colorectal carcinoma survivors, 1975-2001

BACKGROUND

Studies of persons with colorectal cancer have reported increased risk of subsequent primary cancers. Results have not been consistent, however, and there is little information about such risk in specific races and ethnic populations.

METHODS

Using 1975-2001 data from the Surveillance, Epidemiology, and End Results (SEER) Program, we assembled 262,600 index cases of colorectal carcinoma to assess the occurrence of subsequent primary cancers in 13 noncolonic sites. Observed (O) subsequent cancers were compared with those expected (E) based on age-/sex-/race-/year-/site-specific rates in the SEER population. The standardized incidence ratio (SIR) and the absolute excess risk (AER) represent 'O / E' and 'O - E,' respectively.

RESULTS

Colorectal carcinoma patients had significantly elevated SIRs for small gut, stomach (males), kidney, and corpus uteri cancers, ranging from 1.13 for stomach cancer in males to 3.45 for small gut cancer in females. Elevated SIRs for additional sites were seen in certain population subgroups: pancreas and ovary in persons aged <50 years, and prostate in black males. The excess burden, as assessed by AER, was notable for prostate cancer in black males and for corpus uteri cancer in females aged <50 years (26.5 and 9.5 cancers per 10,000 person-years, respectively), and it persisted beyond 5 years of follow-up.

CONCLUSIONS

Although significantly elevated SIRs were found for several cancers, the excess burden was notable only for cancer of the prostate in black males and of the corpus uteri in females under age 50.

Carcinomas of the female genital tract occurring after pelvic irradiation: a report of 15 cases

The concept of postradiation sarcoma is widely appreciated, however carcinomas arising in previously irradiated fields, the putative "postradiation carcinoma," are less well understood. Fifteen patients who developed gynecological malignancies after pelvic radiation therapy were studied. Five of these patients had HPV-related tumors both pre- and post- irradiation. Ten were irradiated for cervical cancer, one for endometrial carcinoma, one for vulvar carcinoma, one for colon cancer and 2 for benign conditions. The mean and median latent periods from the initiation of radiation therapy to the development of the second malignancy were 22.8 and 19 years, respectively (22.4 and 19.5 years, respectively, for non-HPV-related cancers; 24 and 18 years for HPV-related cancers). The "postradiation" malignancies included 2 ovarian carcinomas, 5 vaginal carcinomas (3 invasive, 2 in situ), 4 endometrial carcinomas, one cervical carcinoma, one vulvar carcinoma, one distal urethral carcinoma, and one pelvic carcinoma of unclear primary site. Gynecological carcinomas may occur many years after pelvic irradiation. Although the evidence for a causative role is circumstantial, these tumors appear to have a similar latent period as postradiation sarcomas.

An analysis of SEER data of increasing risk of secondary malignant neoplasms among long-term survivors of childhood brain tumors

BACKGROUND

Advances made in treatment of a childhood brain cancer have extended the lives of many children and adolescents. Treatment success, however, brings the opportunity to assess late effects; most worrying among these are secondary malignant neoplasms (SMN). Even though the cumulative incidence is quite small, long-term follow-up is required because treatment-induced cancers can occur years after initial treatment.

PROCEDURE

The purpose of this project was to determine what treatments and what host characteristics of children treated for a primary brain cancer are associated with an increase in the risk of a SMN in long-term survivors. Data were analyzed from 2,056 5-year survivors, of primary brain cancer in the surveillance, epidemiology, and end results (SEER) database between 1973 and 1998. Thirty-nine patients developed a SMN. Cox regression models were used to evaluate the independent contribution of a number of risk factors.

RESULTS

The most important risk factor for developing a SMN in 5-year survivors was the era in which the primary cancer was treated. Compared to treatment prior to 1979, patients treated between 1979 and 1984 had a 4.7-fold increase in risk (P = 0.001), while those treated after 1985 had a 6.7-fold increase in risk. (P = 0.002). Patients treated most recently carry the greatest risk of SMN development even after controlling for radiotherapy. This could be due to the increase in intensive treatment compared to earlier years.

CONCLUSION

Although the absolute excess risk of SMN remains quite low, continued surveillance is needed to evaluate long-term effects of new therapies for primary brain tumors.