Radiotherapy in mantle cell lymphoma: A literature review.

Mantle cell lymphoma (MCL) is a B-cell malignancy, comprising between 3% and 10% of all adult-onset non-Hodgkin lymphomas. MCL is considered incurable with current treatment modalities and most patients require multiple lines of treatment during their lifetime. MCL is very sensitive to radiotherapy (RT), even when delivered in low doses. In limited-stage MCL, RT can enable the de-escalation of systemic therapy. RT monotherapy is a valid option for frail patients. In advanced-stage disease, RT is very potent mode of palliation, even in heavily pretreated and chemo-resistant patients. Furthermore, it can provide a respite during which systemic treatment is unnecessary. In general, RT has a favorable toxicity profile and can be repeated as necessary for local relapse or distant disease. This effective, safe, and relatively inexpensive modality of therapy has been underutilized for patients with MCL. In this review, we will outline the use of RT for limited and advanced-stage disease and its potential application in combination with novel drugs.

Papillary Thyroid Cancers with Focal Tall Cell Change are as Aggressive as Tall Cell Variants and Should Not be Considered as Low-Risk Disease.

BACKGROUND: The tall cell variant of papillary thyroid carcinoma (PTC) is as an aggressive histological variant. The proportion of tall cells needed to influence prognosis is debated. METHODS: Patients with PTC and tall cells, defined as having a height-to-width ratio of ≥ 3:1, seen at a high-volume center between 2001 and 2015, were reviewed. Specimens were classified as (1) focal tall cell change, containing < 30% of tall cells; (2) tall cell variant, ≥ 30% of tall cells; and (3) control cases selected from infiltrative classical PTCs without adverse cytologic features. Univariate, sensitivity, and multivariate analyses were performed with persistent/recurrent disease as the primary outcome. RESULTS: We identified 96 PTCs with focal tall cell change, 35 with the tall cell variant and 104 control cases. Factors associated with poor clinical prognosis were significantly greater in those with focal tall cell change and tall cell variants. Regarding primary outcome, hazard ratios were 2.3 (95% confidence interval [CI] 1.0-5.7) for focal tall cell change, and 3.4 (95% CI 1.2-8.7) for tall cell variants compared with controls. Five-year disease-free survival was higher for the control group (92.7%, CI 87.4-98.0) compared with focal tall cell change (76.3%, CI 66.1-86.5) and the tall cell variant (62.2%, CI 43.2-81.2). When stratified in groups consisting of tall cell proportions (< 10%, 10-19%, 20-29% and ≥ 30%), identification of ≥ 10% tall cell change was associated with worse outcome (p = 0.002). CONCLUSIONS: PTCs with ≥ 10% tall cell change have worse prognosis than those without tall cells. Our data indicate that thyroid cancer management guidelines should consider PTCs with focal tall cell change outside of the low-risk classification.

Thyroid cancer patient perceptions of radioactive iodine treatment choice: Follow-up from a decision-aid randomized trial.

BACKGROUND: Patient decision aids (P-DAs) inform medical decision making, but longer term effects are unknown. This article describes extended follow-up from a thyroid cancer treatment P-DA trial. METHODS: In this single-center, parallel-design randomized controlled trial conducted at a Canadian tertiary/quaternary care center, early-stage thyroid cancer patients from a P-DA trial were contacted 15 to 23 months after randomization/radioactive iodine (RAI) decision making to evaluate longer term outcomes. It was previously reported that the use of the computerized P-DA in thyroid cancer patients considering postsurgical RAI treatment significantly improved medical knowledge in comparison with usual care alone. The P-DA and control groups were compared for the following outcomes: feeling informed about the RAI treatment choice, decision satisfaction, decision regret, cancer-related worry, and physician trust. In a subgroup of 20 participants, in-depth interviews were conducted for a qualitative analysis. RESULTS: Ninety-five percent (70 of 74) of the original population enrolled in follow-up at a mean of 17.1 months after randomization. P-DA users perceived themselves to be significantly more 1) informed about the treatment choice (P = .008), 2) aware of options (P = .009), 3) knowledgeable about treatment benefits (P = .020), and 4) knowledgeable about treatment risks/side effects (P = .001) in comparison with controls. There were no significant group differences in decision satisfaction (P = .142), decision regret (P = .199), cancer-related worry (P = .645), mood (P = .211), or physician trust (P = .764). In the qualitative analysis, the P-DA was perceived to have increased patient knowledge and confidence in decision making. CONCLUSIONS: The P-DA improved cancer survivors' actual and long-term perceived medical knowledge with no adverse effects. More research on the long-term outcomes of P-DA use is needed.

Clinical characteristics and early treatment outcomes of follicular lymphoma in young adults.

Follicular lymphoma (FL) in young adults (YA, <40 years old) is uncommon, and the clinical characteristics and outcomes of this group are not well defined. We conducted a retrospective database review of 427 patients with newly diagnosed FL aged 65 years or less registered at Princess Margaret Cancer Centre between 1995 and 2010. YA (n = 61) and those 40-65 (n = 366) were compared with regards to clinical stage at diagnosis, FL International Prognostic Index (FLIPI) score, and the following clinical outcomes: time to second treatment, cause-specific survival (CSS) and overall survival (OS). At diagnosis, stage and FLIPI score were similar, as were the proportion of patients requiring therapy (YA 75% versus older adults 71%). Median follow-up was 8.1 years. Time to second therapy was similar in both age groups (5-year probability 23% YA versus 27% older adults; Gray's P-value = 0.76). Ten-year OS was significantly higher for YA (87% versus older adults 72%; P = 0.029). On multivariate analysis, age <40 years, low FLIPI score and observation as initial management were favourable prognostic factors for OS and CSS. We conclude that YA with FL have a favourable prognosis compared to older patients; whether this reflects competing mortality risks or age-related differences in lymphoma biology warrants further investigation.

Exploring the relationship between patients' information preference style and knowledge acquisition process in a computerized patient decision aid randomized controlled trial.

BACKGROUND: We have shown in a randomized controlled trial that a computerized patient decision aid (P-DA) improves medical knowledge and reduces decisional conflict, in early stage papillary thyroid cancer patients considering adjuvant radioactive iodine treatment. Our objectives were to examine the relationship between participants' baseline information preference style and the following: 1) quantity of detailed information obtained within the P-DA, and 2) medical knowledge. METHODS: We randomized participants to exposure to a one-time viewing of a computerized P-DA (with usual care) or usual care alone. In pre-planned secondary analyses, we examined the relationship between information preference style (Miller Behavioural Style Scale, including respective monitoring [information seeking preference] and blunting [information avoidance preference] subscale scores) and the following: 1) the quantity of detailed information obtained from the P-DA (number of supplemental information clicks), and 2) medical knowledge. Spearman correlation values were calculated to quantify relationships, in the entire study population and respective study arms. RESULTS: In the 37 P-DA users, high monitoring information preference was moderately positively correlated with higher frequency of detailed information acquisition in the P-DA (r = 0.414, p = 0.011). The monitoring subscale score weakly correlated with increased medical knowledge in the entire study population (r = 0.268, p = 0.021, N = 74), but not in the respective study arms. There were no significant associations with the blunting subscale score. CONCLUSIONS: Individual variability in information preferences may affect the process of information acquisition from computerized P-DA's. More research is needed to understand how individual information preferences may impact medical knowledge acquisition and decision-making.

Patients' experiences following local-regional recurrence of thyroid cancer: a qualitative study.

BACKGROUND AND OBJECTIVE: The psychosocial impact of local-regional thyroid cancer recurrence is not known. The aim of this study was to explore thyroid cancer patients' experiences relating to diagnosis and treatment of local-regional disease recurrence. METHODS: We conducted 15 semi-structured interviews with survivors of differentiated thyroid cancer who underwent neck reoperation for recurrent disease. Participants were recruited from the clinical practices of thyroid surgeons and endocrinologists at University Health Network and Mount Sinai Hospitals in Toronto, Ontario. Participant interviews were audio-recorded, transcribed verbatim, and analyzed using qualitative methods. Saturation of themes was achieved. RESULTS: Local-regional recurrence of thyroid cancer was associated with significant psychological distress. Confidence in healthcare providers as well as psychosocial support from family or social relations, were helpful in coping with disease recurrence. After recovery from treatment, post-traumatic growth was reported. However, questions and worry about the risk for future recurrence lingered at follow-up. CONCLUSIONS: Local-regional recurrence of thyroid cancer has a significant psychosocial impact on patients, and support needs are heightened throughout the experience. Healthcare providers should strive to ensure that medical information and psychosocial needs of such patients are met, throughout the treatment experience, as well as at follow-up.

A population-based study of cardiac morbidity among Hodgkin lymphoma patients with preexisting heart disease.

The risk of cardiac hospitalization (CH) in Hodgkin lymphoma (HL) patients with preexisting heart disease was evaluated. Patients with HL were identified from a population-based registry (N = 3964). Data were abstracted from records of a randomly selected subcohort (N = 1096). A population-based registry was used to identify CH. Factors associated with CH and the incidence of CH after HL were estimated with competing risk models. Preexisting heart disease was the strongest predictor of posttreatment CH (hazard ratio = 3.98, P < .001) and significantly modified (P = .01) the effect of treatment on the risk of CH. Among patients with preexisting heart disease, treatment with mediastinal radiation therapy plus doxorubicin-based chemotherapy was associated with a 10-year incidence of CH more than 20% higher than treatment with chemotherapy alone. There is a high risk of CH after mediastinal radiation therapy plus doxorubicin-based chemotherapy among patients with preexisting heart disease; this is an important consideration when weighing treatment options, and in the follow-up of these patients.

Influence of age on long-term net survival benefit for early-stage MALT lymphomas treated with radiotherapy: A SEER database analysis (2000-2015).

BACKGROUND: Given the lower incidence of lymphoma-related death but higher background mortality in patients with early-stage mucosa-associated lymphoid tissue (MALT) lymphoma, it is critically important to examine how age affects a treatment's survival benefit. METHODS: 9,467 patients with early-stage MALT lymphoma in the Surveillance, Epidemiology, and End Results (SEER) database treated between 2000-2015 were extracted and analyzed. Primary therapy was classified as radiotherapy (n = 3,407), chemotherapy (n = 1,294), and other/unknown treatments including observation (n = 4,766). Inverse probability of treatment weighting (IPTW) was conducted to balance baseline characteristics between groups. Relative survival (RS), standardized mortality ratio (SMR), and transformed Cox regression were conducted to compare survival differences between treatment modalities by controlling for the background mortality. Radiotherapy-age interaction was examined. RESULTS: Across age-groups, early-stage MALT lymphoma patients were at lower risk of lymphoma-related death than death due to other causes. The 10-year overall survival (OS, 73.8 %) and RS (96.6 %) rates were significantly higher, and the SMR (1.14) significantly lower, with radiotherapy than with chemotherapy (OS, 61.7 %; RS, 86.4 %; SMR, 1.54; P < 0.001) or other/unknown treatments (OS, 61.1 %; RS, 87.2 %; SMR, 1.41; P < 0.001). By multivariable analysis and IPTW, radiotherapy remained an independent predictor of better RS (HR 0.81, 95 %CI, 0.73-0.89; P < 0.001). A significant interaction between age and radiotherapy was identified for both RS (Pinteraction = 0.016) and OS (Pinteraction = 0.024), indicating greater benefit in young adults. CONCLUSION: Radiotherapy was associated with significantly better survival in early-stage MALT lymphoma, especially in young adults.

CLIPI: a new prognostic index for indolent cutaneous B cell lymphoma proposed by the International Extranodal Lymphoma Study Group (IELSG 11).

Indolent primary cutaneous B cell lymphomas (PCBCL) generally have a good prognosis, but they often relapse leading in some cases to extracutaneous disease and therefore, to poor survival. We developed a prognostic model to improve the therapeutic approach to these lymphomas. Two hundred and seventeen patients with diagnosis of indolent PCBCL stage IE or IIE were assessed retrospectively. The prognostic model was built to fit a Cox proportional hazard model using all the covariates affecting progression-free survival (PFS) at p<0.1 in the univariate analysis, and the final model was selected based on the Bayes Information Criteria. Elevated serum lactate dehydrogenase, morphology of the lesion (nodule vs. other), and >2 lesions were independent predictors for PFS. To each prognostic factor was assigned a value of 1. Patients were then stratified to three risk groups: score 0 (28%), low risk; score 1 (55%), intermediate risk; score 2 and 3 (17%), high risk with a 5-year PFS of 91%, 64%, and 48%, respectively (p<0.001). The CLIPI is an easily applicable prognostic index and represents a promising tool for risk-adapted treatment strategies. However, it needs to be addressed in prospective clinical studies.

Involved field radiotherapy for limited stage Hodgkin lymphoma: balancing treatment efficacy against long-term toxicities.

Limited stage Hodgkin lymphoma (HL) refers to patients with stage IA or IIA disease in the absence of any bulky mass or unfavourable prognostic factors. In this group, the long-term disease control with treatment can be expected in more than 90%, and management has now been directed to make strategies to reduce late morbidities related to therapy. With the advent of very effective chemotherapy, the role of radiation therapy has evolved from a first line single modality treatment, to an adjuvant therapy following brief cycles of chemotherapy. Optimal radiation volume and dose parameters have been refined in the combined modality setting. Furthermore, with the progress in diagnostic functional imaging and advances in radiotherapy, it is possible to accurately deliver low to moderate doses of radiation to defined regions resulting in durable control of disease. This review will evaluate the literature that shapes the current standard of care in limited stage Hodgkin lymphoma with special emphasis on the use of limited field radiotherapy.

A pilot study examining Toronto-area family physician perspectives on thyroid neoplasm evaluation.

OBJECTIVE: The incidence of thyroid cancer (TC) is known to be very high in the Greater Toronto Area of Ontario, Canada. We performed a pilot survey study examining Toronto-area family physician (FP) perspectives on thyroid neoplasm evaluation (i.e. thyroid nodules [TNs] or thyroid cancer [TC]) in this region, to explore for potential factors leading to overdiagnosis. METHODS: We performed a cross-sectional mail-out written survey of a random sample of 300 FPs in active practice in the Greater Toronto Area (Markham and Brampton). RESULTS: The overall response rate was 22.3, 95% confidence interval (CI) 18.0, 27.4% (67/300); the effective response rate was 19.9, 95% CI 15.7, 24.9% (58/291), after excluding 6 FPs that reported TN evaluation was outside their scope of practice and three FPs with an invalid mailing address. There were no missing responses to questions. The demographic characteristics were as follows: 58.6% (34/58) from Markham, 55.2% (32/58) were female, 58.6% (34/58) were in practice > 10 years, and 32.8% (19/58) affiliated with a University. All FPs reported easy access to thyroid ultrasound (TUS). About half of FPs were concerned about overdiagnosis of TC and most did not believe that there was any TC survival advantage with routine screening TUS. Although appropriate indications for TUS were endorsed by most respondents (e.g. palpable TN, incidental TN on other imaging), inappropriate recommendations were observed in a third of FPs (19/57) who recommended TUS for abnormal thyroid blood tests about half of FPs (30/56) who endorsed biopsy of sub-centimeter nodules. About half of FPs (31/58) reported that their patients sometimes request medically unnecessary TUS. CONCLUSION: There are likely multiple complex factors leading to potential overdiagnosis of TC in primary care, including some physicians' knowledge gaps about appropriate indications for TN investigations as well as patients' requests and expectations.

External beam radiation therapy for thyroid cancer.

This article discusses the role of external beam radiotherapy (XRT) in the management of well-differentiated thyroid cancer (WDTC), medullary thyroid cancer, and anaplastic thyroid cancer. Although there are no randomized controlled studies on the use of XRT in thyroid cancer, evidence supports its use to treat gross disease after surgery or unresectable cancer and its use as an adjuvant after resection of a known high-risk disease in WDTC, and, to a lesser extent, in medullary thyroid cancer. The use of XRT for the palliation of symptomatic disease and recent advances in the technology of radiation delivery also will be discussed.

An updated systematic review and commentary examining the effectiveness of radioactive iodine remnant ablation in well-differentiated thyroid cancer.

Radioactive iodine remnant ablation (RRA) is used to destroy residual normal thyroid tissue after complete gross surgical resection of papillary or follicular thyroid cancer. The article updates a prior systematic review of the literature to determine whether RRA decreases the risk of thyroid cancer-related death or recurrence at 10 years after initial surgery, including data from 28 studies. No long-term randomized trials were identified, so the review is limited to observational studies. The incremental benefit of RRA in low risk patients with well-differentiated thyroid cancer after total or near-total thyroidectomy who are receiving thyroid hormone suppressive therapy remains unclear.

A systematic review examining the effects of therapeutic radioactive iodine on ovarian function and future pregnancy in female thyroid cancer survivors.

BACKGROUND: For women with differentiated thyroid carcinoma (DTC), the effect of radioactive iodine (RAI) therapy on gonadal and reproductive function is an important consideration. OBJECTIVE AND METHODS: We systematically reviewed controlled studies examining the gonadal and reproductive effects of RAI therapy in women and adolescents surviving DTC. We searched nine electronic databases. All abstracts and papers were independently reviewed by two reviewers. RESULTS: After reviewing 349 unique citations and 61 full-text papers, 16 papers including data from 3023 women or adolescents with DTC were included. All studies were observational, with no long-term randomized control trial data. The age at first RAI treatment varied from 8 to 50 years and the cumulative activities of RAI administered for treatment varied from 30 to 1099 mCi. Transient absence of menstrual periods occurred in 8-27% of women within the first year after RAI, particularly in older women. In addition, RAI-treated women experienced menopause at a slightly younger age than women not treated with RAI. In the first year after RAI therapy, several studies reported increased rates of spontaneous and induced abortions. However, RAI treatment for DTC was generally not associated with a significantly increased risk of long-term infertility, miscarriage, induced abortions, stillbirths, or offspring neonatal mortality or congenital defects. CONCLUSIONS: In female survivors of DTC, there is little observational evidence to suggest important adverse effects of RAI treatment on gonadal function, fertility or pregnancy outcomes beyond 12 months, with the exception of a possible slightly earlier age of menopause.

A systematic review of the gonadal effects of therapeutic radioactive iodine in male thyroid cancer survivors.

BACKGROUND: For patients with well-differentiated thyroid carcinoma (WDTC), the gonadal effects of radioactive iodine (RAI) therapy is an important consideration. OBJECTIVE AND METHODS: We systematically reviewed the controlled studies examining the gonadal effects of RAI therapy in male WDTC survivors. We searched in nine electronic databases. All abstracts and papers were independently reviewed by two reviewers. RESULTS: After reviewing 334 abstracts and 59 full-text papers, seven papers were included. In longitudinal studies examining the effect of single primary RAI dose activities of 594 mCi. Cumulative RAI dose correlated with FSH measurements at long-term follow-up. In one study, approximately one in eight men experienced oligospermia 1 year after RAI therapy. Rates of infertility, pregnancy loss and offspring congenital malformation were not elevated, but studies were limited by small size and self-reported outcomes. CONCLUSIONS: Abnormalities in testicular function are common within several months of a single therapeutic dose of RAI for WDTC. Biochemical abnormalities usually resolve within 18 months after administration of a single activity of < 150 mCi of RAI. The risk of persistent gonadal dysfunction is increased after repeated or high cumulative RAI activities. Controlled, prospective studies, with long-term follow-up, examining male gonadal and offspring effects of RAI therapy are needed.

Radiation Therapy for Solitary Plasmacytoma and Multiple Myeloma: Guidelines From the International Lymphoma Radiation Oncology Group.

PURPOSE: To develop guidelines for the work-up and radiation therapy (RT) management of patients with plasma cell neoplasms. METHODS AND MATERIALS: A literature review was conducted covering staging, work-up, and RT management of plasma cell neoplasms. Guidelines were developed through consensus by an international panel of radiation oncologists with expertise in these diseases, from the International Lymphoma Radiation Oncology Group. RT volume definitions are based on the International Commission on Radiation Units and Measurements. RESULTS: Plasma cell neoplasms account for approximately one-fifth of mature B-cell neoplasms in the United States. The majority (∼95%) are diagnosed as multiple myeloma, in which there has been tremendous progress in systemic therapy approaches with novel drugs over the last 2 decades, resulting in improvements in disease control and survival. In contrast, a small proportion of patients with plasma cell neoplasms present with a localized plasmacytoma in the bone, or in extramedullary (extraosseous) soft tissues, and definitive RT is the standard treatment. RT provides long-term local control in the solitary bone plasmacytomas and is potentially curative in the extramedullary cases. This guideline reviews the diagnostic work-up, principles, and indications for RT, target volume definition, treatment planning, and follow-up procedures for solitary plasmacytoma. Specifically, detailed recommendations for RT volumes and dose/fractionation are provided, illustrated with specific case scenarios. The role of palliative RT in multiple myeloma is also discussed. CONCLUSIONS: The International Lymphoma Radiation Oncology Group presents a standardized approach to the use and implementation of definitive RT in solitary plasmacytomas. The modern principles outlining the supportive role of palliative RT in multiple myeloma in an era of novel systemic therapies are also discussed.

A Systematic Review and Meta-Analysis of Subsequent Malignant Neoplasm Risk After Radioactive Iodine Treatment of Thyroid Cancer.

Background: The potential risk of subsequent malignant neoplasms (SMNs) after radioactive iodine (RAI) treatment of thyroid cancer (TC) is an important concern. Methods: A systematic review was updated comparing the risk of SMNs in TC patients treated with RAI to TC patients without RAI. Six electronic databases were searched (up to March, 2018), supplemented with a hand search. Two reviewers independently screened citations, reviewed full-text papers, and critically appraised/abstracted data. Random-effects meta-analyses were conducted using crude data and data statistically adjusted for confounders. The outcomes were any SMN and specific SMNs for which sufficient data were available. Results: In total, 3506 unique electronic search citations and 93 full-text papers were examined, including 17 studies (3 systematic reviews and 14 original studies). Published knowledge syntheses were limited by inclusion of small numbers of studies, with two systematic reviews suggesting an increased risk of any SMN and one meta-analysis suggesting a reduced risk of breast SMN after RAI treatment. In a meta-analysis of crude data, the risk ratio of any SMN in RAI-treated TC patients was 0.98 ([confidence interval (CI) 0.76-1.27]; n = 10 studies of 65,539 individuals, heterogeneity Q = 64.26, degrees of freedom [df] = 9, p < 0.001, I2 = 85.99). The pooled risk ratio for any SMN, adjusted for confounders, was 1.16 ([CI 0.97-1.39]; n = 6 studies, data from at least 11,241 TC patients, Q = 10.86, df = 5, p = 0.054, I2 = 53.96). In secondary analyses examining specific SMNs, although relatively rare, the risk of subsequent leukemia was increased, but the risk of multiple myeloma was reduced in RAI-treated TC patients. There was no significant increased relative risk of breast cancer, salivary cancer, or combined hematologic malignancies according to RAI treatment status. Conclusions: The body of evidence on whether 131I treatment of thyroid cancer is associated with the primary outcome of any SMN is highly heterogeneous and complex. More research examining the long-term risk of specific SMNs after 131I treatment is needed.

Low-grade non-hodgkin lymphomas.

The most common low-grade non-Hodgkin lymphomas are of B-cell origin. This review will focus on follicular lymphomas and extranodal marginal zone lymphomas, also known as mucosa-associated lymphoid tissue (MALT) lymphomas. These are radiation-sensitive lymphomas. Moderate doses (30-35 Gy) for these stage I and II low-grade lymphomas result in long-term local control and possible cure. Involved-field radiation therapy is the standard approach and produces minimal morbidity. However, a significant proportion of patients relapse with systemic disease outside of radiation fields. For follicular lymphoma, this occurs in approximately 50% of patients after 15 years and for nongastric MALT lymphoma 30% to 40% after 10 years. Patients with relapsed disease are not curable with chemotherapy, but the disease often remains indolent and prolonged survival is observed. For gastric MALT lymphomas associated with Helicobacter pylori but which did not respond to antibiotic therapy, radiation treatment is indicated and almost always curative. For localized MALT lymphomas not related to microorganisms, radiation therapy is the initial standard therapy regardless of anatomic location. Patients with stage III and IV low-grade lymphoma and local symptoms are often successfully palliated with a low dose regimen of 2 x 2 Gy (total dose 4 Gy).