Thyroid carcinoma after treatment for malignancies in childhood and adolescence: from diagnosis through follow-up

Treating secondary malignant neoplasms: A burden of childhood cancer survivors

Each year approximately 35,000 children and adolescents are diagnosed with cancer in Europe. Five-year survival rates have improved and now reach 80% in most European countries, thanks to a combination of chemotherapy, radiotherapy, and surgery. To date, there are more than 44,000 Italians still living several years after being diagnosed with cancer in developmental age. The risk of premature morbidity and mortality for cancer survivors is well known and documented. Approximately 60% of survivors of cancer in childhood and adolescence have at least one chronic health condition in later life, and more than one in four develop severe or life-threatening disorders. Among the various long-term iatrogenic sequelae of cancer treatments, the most worrisome are second malignant neoplasms. We reported on our mono-institutional experiences of screening and treating secondary breast cancer, secondary thyroid cancer and secondary osteosarcoma. Recommendations on the surveillance needed for cancer survivors because of the risk of late effects of their disease or its treatment suggest that discussing the potential problems early on can be crucial to a patient's future health. These considerations and our consolidated experience strengthen our conviction that survivors of cancer in childhood and adolescence who develop second malignant neoplasms should be treated at highly-specialized centers. Multidisciplinary care requires close communications and high levels of up-to-date professional expertise. This challenging area of health care is also changing rapidly because cancer survivorship is a work in progress, but we cannot wait for definitive conclusions on many aspects because this will take decades, especially for pediatric patients.

Exposure to radiotherapy for first primary cancer as a risk factor for second primary thyroid cancer: A case-control study

BACKGROUND

Second primary neoplasms are associated with high mortality and morbidity rates in cancer survivors successfully treated for the first malignancy. Studies suggested an association between the type of first neoplasm and risk of subsequent thyroid cancer, with part of this risk attributable to exposure to radiotherapy during treatment of the first primary tumor. This study aimed to determine whether radiotherapy is a risk factor for thyroid cancer in patients previously treated for another neoplasm.

METHODS

This retrospective case-control study included patients diagnosed with their first cancer between 2007 and 2017. Patients who subsequently developed thyroid cancer as a second primary neoplasm were defined as "cases", and patients who did not develop a second cancer were defined as "controls". Exposure to radiotherapy was the primary risk factor of interest; other risk factors were the site to which radiotherapy was delivered and the first neoplasm type.

RESULTS

Exposure to radiotherapy was associated with an increased risk of thyroid cancer (odds ratio [OR]=2.410, 95% confidence interval [CI]: 1.219-4.764), in particular, in women (OR=3.121, 95% CI: 1.232-7.907) and in patients receiving radiotherapy to the thorax (OR=6.298, 95% CI: 2.581-15.370). The median survival time from first cancer recovery to thyroid cancer occurrence was 63.80 months; there was no difference in survival between patients who did and did not receive radiotherapy (P=0.899).

CONCLUSION

Radiation to the thorax can increase the risk of thyroid cancer as a second neoplasm among patients with cancer successfully treated for their first cancer.

Ultrasound is superior to palpation for thyroid cancer detection in high-risk childhood cancer and BMT survivors

PURPOSE

Thyroid cancer is a common subsequent malignant neoplasm in childhood cancer survivors (CCS). Patients who received radiotherapy (RT) to the head, neck, upper thorax, or total body irradiation (TBI) are considered to be at risk for subsequent thyroid cancer. Current Children's Oncology Group screening guidelines recommend annual neck palpation. Our objective was to determine if ultrasound (US) is more sensitive and specific than palpation to detect thyroid cancer in high-risk CCS and bone marrow transplant (BMT) survivors.

METHODS

Electronic medical records of patients followed in a longitudinal survivorship clinic from January 1, 2010 to December 31, 2017 were reviewed. Inclusion criteria included history of RT to the head, neck, upper thorax, or TBI for primary therapy or preparation for BMT prior to the age of 20 years.

RESULTS

Two hundred and twenty-five patients had documented palpation and 144 (64%) also had US evaluation. Mean radiation dose was 28.6 Gy. Sixteen of 225 patients (7.1%) developed a subsequent thyroid cancer at a mean of 9.7 years from the completion of RT. Sensitivity of US was 100% compared with 12.5% for palpation. US demonstrated higher accuracy, with a receiver operating characteristic (ROC) area under the curve (AUC) of 0.87 versus 0.56 for palpation (P < 0.0001).

CONCLUSION

Routine screening with US was more sensitive than palpation for detection of subsequent thyroid cancer after high-risk RT in CCS and BMT survivors. Screening US may lead to earlier detection of thyroid cancer in this population. Earlier diagnosis has the potential to decrease operative complexity, and earlier definitive therapy reduces the likelihood of metastatic disease.

Thyroid cancer in adolescents and young adults

In adolescents and young adults, thyroid cancer accounts for 13% of all invasive neoplasms, being three times more frequent in females, but overdiagnosis and overtreatment are common. There are two therapeutic approaches, one radical and no longer preferred in all instances, and the other conservative. Permanent complications of surgery and metabolic irradiation can affect quality of life and carry an economic burden. The overall survival rate approaches 100% for patients with differentiated thyroid cancer regardless of the extent of treatment. Medullary thyroid carcinoma is a very different entity, occurring most frequently in the context of hereditary tumor susceptibility syndromes.

Screening for thyroid cancer in survivors of childhood and young adult cancer treated with neck radiation

BACKGROUND

The optimal method of screening for thyroid cancer in survivors of childhood and young adult cancer exposed to neck radiation remains controversial. Outcome data for a physical exam-based screening approach are lacking.

METHODS

We conducted a retrospective review of adult survivors of childhood and young adult cancer with a history of neck radiation followed in the Adult Long-Term Follow-Up Clinic at Memorial Sloan Kettering between November 2005 and August 2014. Eligible patients underwent a physical exam of the thyroid and were followed for at least 1 year afterwards. Ineligible patients were those with prior diagnosis of benign or malignant thyroid nodules.

RESULTS

During a median follow-up of 3.1 years (range 0-9.4 years), 106 ultrasounds and 2277 physical exams were performed among 585 patients. Forty survivors had an abnormal thyroid physical exam median of 21 years from radiotherapy; 50% of those with an abnormal exam were survivors of Hodgkin lymphoma, 60% had radiation at ages 10-19, and 53% were female. Ultimately, 24 underwent fine needle aspiration (FNA). Surgery revealed papillary carcinoma in seven survivors; six are currently free of disease and one with active disease is undergoing watchful waiting. Among those with one or more annual visits, representing 1732 person-years of follow-up, no cases of thyroid cancer were diagnosed within a year of normal physical exam.

CONCLUSIONS

These findings support the application of annual physical exam without routine ultrasound for thyroid cancer screening among survivors with a history of neck radiation.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors with a history of neck radiation may not require routine thyroid ultrasound for thyroid cancer screening. Among adult survivors of childhood and young adult cancer with a history of radiation therapy to the neck, annual physical exam is an acceptable thyroid cancer screening strategy.

Relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents - a report from the United Kingdom's Children's Cancer and Leukaemia Study Group

There is a paucity of data on the treatment outcome in children with relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma (nLPHL). This retrospective report evaluates the treatment outcome in a national cohort of children with relapsed or poorly responsive nLPHL. A total of 37 patients, 22 with relapsed and 15 with poorly responding disease, are the subjects of this report. Of the 22 patients with relapsed nLPHL, 11 had relapsed after primary excision biopsy, 10 after chemotherapy and 1 after chemotherapy and involved field radiotherapy. The majority had localized disease at relapse. The median time to relapse was 8 months after chemotherapy and 11 months after excision biopsy. Seven of the 15 patients with poorly responding nLPHL had variant histology. Three patients with initial poor response did not receive any further treatment and have had no disease progression. Transformation to diffuse large B cell lymphoma, in addition to evolution from typical to variant nLPHL occurred in one patient each. Thirty-four patients have been successfully re-treated with second chemotherapy or radiotherapy. Multiple relapses were uncommon but treatable. Relapse or poorly responsive nLPHL is fully salvageable with either additional chemotherapy and or radiotherapy.

Follicular variant papillary thyroid carcinoma in a pediatric population

BACKGROUND

Follicular variant of papillary thyroid carcinoma (FVPTC) has been shown to be an intermediate entity between papillary (PTC) and follicular/Hurtle cell (FTC) thyroid carcinoma in adults. However, the tumor characteristics and prognosis of FVPTCs has not been studied in the pediatric population and is the focus of the current study

METHODS

All pediatric patients ≤ 19 years of age with differentiated thyroid cancer (PTC, FVPTC, or FTC) were identified from the SEER registry from 1988-2009. Patients were divided into groups based on their histology. Adjusted odds ratios (ORs) for demographic, tumor, and treatment characteristics, as well as hazard ratios (HRs) for overall (OS) and disease-specific survival (DSS) were calculated for FVPTC.

RESULTS

Of 1,956 patients, 445 (22.7%) had FVPTC. Compared to PTCs, FVPTCs were larger (OR: 2.03, CI:1.35-3.06), node negative (OR: 2.26, CI:1.61-3.19), occurred more often in patients < 15 years of age (OR: 1.58, CI:1.10-2.27), and had a partial thyroidectomy (OR: 1.61, CI:1.01-2.57). Conversely, compared to FTC, FVPTCs tumors were smaller (OR: 2.78, CI:1.70-4.53), node positive (OR: 5.26, CI:2.74-10.11), a first cancer (OR: 4.98, CI:2.48-9.99), and more often had a total thyroidectomy (OR: 2.84, CI:1.70-4.76). Only tumor size > 4 cm (HR: 13.92, CI:1.24-156.72) influenced OS for patients with FVPTC. There was no significant difference in OS or DSS between groups.

CONCLUSIONS

In pediatric patients ≤ 19 years of age, FVPTCs have intermediate tumor features compared to PTC and FTC, but a similar OS and DSS. All pediatric patients with thyroid cancer require lifelong surveillance. However, FVPTCs > 4 cm may warrant closer follow-up due to an increased risk of death.

Pediatric Thyroid Microcarcinoma

BACKGROUND

Thyroid microcarcinomas (TMCs) are increasing in the general population, most commonly in older individuals; however, the incidence, characteristics, and outcomes of TMCs in pediatric patients has not been studied.

METHODS

All patients ≤19 years of age with differentiated thyroid carcinoma (DTC) were identified from the surveillance, epidemiology, and end results registry from 1988 to 2009. Patients were divided into two groups based on tumor siz e: TMCs (≤1 cm) and tumors >1 cm. Demographic, tumor, and treatment characteristics, as well as overall survival (OS) and disease-specific survival (DSS), were compared between the two groups. The TMC group was analyzed separately for predictors of overall and disease-specific death.

RESULTS

Of 1825 pediatric DTC patients, 8.4 % had a TMC, and, over the past decade, the incidence has decreased (6.5 vs 14.5 %; p < 0.001). Compared to patients with DTCs >1 cm, TMCs were more likely to have papillary histology, negative lymph nodes, be treated with a partial thyroidectomy [odds ratio (OR) 3.46, CI 2.02-5.93] and not receive radioiodine (OR 1.77, CI 1.10-2.83). Neither OS (TMC: 253.59 months; DTC >1 cm: 257.97 months) nor DSS (TMC: 256.38 months; DTC >1 cm: 260.77 months) differed between groups. Predictors of decreased OS in the entire cohort included secondary malignancy status (p = 0.001), black race (p = 0.006) and follicular or Hurthle histology (p = 0.001). In patients with primary TMC, only follicular or Hurthle histology (p = 0.001) predicted decreased OS.

CONCLUSIONS

TMCs in patients ≤19 years of age are declining and comprise <10 % of pediatric thyroid malignancies. TMCs are most commonly treated with a partial thyroidectomy not followed by radioiodine, and have an excellent OS and DSS.