Skin cancer management-updates on Merkel cell carcinoma.

There are many different types of skin tumors in the World Health Organization (WHO) classification. The natural course and treatment varies according to the histological type. This review summarizes clinical experience for treatment decision. Contemporary radiotherapy and systemic therapy are improving. Landmark studies for basal cell and Merkel cell carcinomas (MCC) trigger further research and impetus for improving treatment outcome. Avelumab, nivolumab, pembrolizumab, ipilimumab appear to be promising for treatment of advanced MCCs and adjuvant trials are underway.

Spontaneous Regression of Merkel Cell Carcinoma of the Male Breast with Ongoing Immune Response.

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine tumor arising predominantly on sun-exposed skin among the elderly. The most common location is the head and neck, followed by the extremities. MCCs are highly aggressive tumors and rarely undergo spontaneous regression. We report a case of MCC which presented as a painless breast lump in an elderly male where the tumor regressed spontaneously after a biopsy.

Cardiac-sparing radiation therapy using positioning breast shell for patients with left-sided breast cancer who are ineligible for breath-hold techniques.

PURPOSE: Patients with left-sided breast cancer (LSBC) are at increased risk of cardiac morbidity from adjuvant breast radiation therapy (ABRT). Breath-hold (BH) techniques substantially reduce the radiation received by heart during radiation therapy for LSBC. However, a subset of patients with LSBC are ineligible for BH techniques due to an inability to breath-hold or because of other comorbidities. To reduce radiation to the heart, we routinely use a custom-made breast shell for the treatment of patients with LSBC who are ineligible for BH techniques. This study evaluates the dosimetric impact of using a breast shell for patients with LSBC undergoing ABRT. METHODS AND MATERIALS: Sixteen consecutive patients with LSBC who failed BH and underwent ABRT using a breast shell during the period of 2014 to 2016 were identified. Treatment was planned using field-in-field tangents with a prescribed dose of 42.5 Gy in 16 fractions. Comparisons between plans with and without a shell were made for each patient using a paired t test to quantify the sparing of organs at risk (OARs) and target coverage. RESULTS: There was no statistically significant difference in the planning target volume of breast coverage. A statistically significant improvement was observed in sparing the heart, left ventricle (LV), and ipsilateral lung (P-value < .001). Plans with the shell spared OARs better than the no-shell plans with a mean dose of 2.15 Gy versus 5.15 Gy (58.2% reduction) to the heart, 3.27 Gy versus 9.00 Gy (63.7% reduction) to the LV, and 5.16 Gy versus 7.95 Gy (35% reduction) to the ipsilateral lung. The irradiated volumes of OARs for plans with and without shell are 13.3 cc versus 59.5 cc (77.6% reduction) for the heart, 6.2 cc versus 33.2 cc (81.2% reduction) for the LV, and 92.8 cc versus 162.5 cc (42.9% reduction) for the ipsilateral lung. CONCLUSIONS: A positioning breast shell offers significant benefit in terms of sparing the heart for patients with LSBC who are ineligible for BH techniques. It also can be used as a simple cardiac-sparing alternative in centers without BH capability.

Issues in Managing Hurthle Cell Carcinoma of Thyroid: A Case Report.

A 61-year-old woman noticed a right neck lump in October 2001. Fine needle aspiration showed follicular neoplasm, adenoma versus carcinoma. The ultrasound scan showed a solid mass of maximum dimension of 3.7 cm. She had a right thyroid lobectomy and isthmectomy in January 2002 (first surgery). The tissue specimen showed a 4.5 cm Hurthle cell carcinoma (HCC) with vascular invasion. There were no capsular invasion, extra-thyroidal extension, or margin involvement. A completion left lobectomy (second surgery) was performed two weeks later. Therefore the pathological stage is II (T3N0M0). She received adjuvant radioactive iodine ablation for residual thyroid tissue. By 2003, she developed local recurrence, which was resected (third surgery), followed by adjuvant external beam radiotherapy. Unfortunately, she developed further recurrence in the left main bronchus, as identified by Indium-111 Octreotide (Curium, Missouri, USA) and positron emission tomography-computed tomography PET-CT imaging in 2006. She underwent a left pneumonectomy (fourth surgery) in July 2006. In November 2007 she was found to have mediastinal recurrence which was treated with high-dose external beam radiotherapy. She initially responded but developed more local recurrence and a lung metastasis by 2011. She was treated with brivanib with ixabepilone, under a phase I clinical trial with mixed response. Her treatment was discontinued secondary to toxicity and she succumbed to her disease in 2012. This case report illustrates the natural history and clinical decision making for patients diagnosed with HCC of the thyroid. Specifically, we highlight the clinical issues surrounding the histopathological diagnosis, extent of surgical resection, radioiodine diagnostic imaging/ablative treatment, as well as external beam radiotherapy.

Radiotherapy in Gorlin Syndrome: Can It Be Safe and Effective in Adult Patients?

Gorlin syndrome, also known as nevoid basal cell carcinoma syndrome, is a rare autosomal dominant disorder with multiple manifestations including early onset of cutaneous basal cell carcinomas (BCCs). Radiotherapy has traditionally been contraindicated due to reports of BCC induction. We describe here a patient treated successfully with radiotherapy with no tumour induction at 57 months of follow-up. A comprehensive literature review of radiotherapy outcomes in patients with Gorlin syndrome suggests radiotherapy may be a feasible treatment option for adult patients with treatment refractory lesions or surgical contraindication.

Male Breast Cancer Prognostic Factors Versus Female Counterparts with Propensity Scores and Matched-Pair Analysis.

OBJECTIVE: To assess the effect of prognostic factors and their impact on survival in male and female breast cancer. METHODS: Medical records for men and women diagnosed with breast cancer referred to the cancer center for treatment were reviewed. Patients with distant metastatic diseases were excluded. Data on prognostic factors including age, nodal status, resection margin, use of hormonal therapy, chemotherapy with and without hormone and radiation therapy (RT), survival, and recurrence were analyzed. Survival estimates were obtained using Kaplan-Meier methodology. The Cox regression interaction was used to compare male and female differences in prognostic factors. Male breast cancer (MBC) and female breast cancer (FBC) were matched according to propensity scores and survival compared using Cox regression. RESULTS: From 1963-2006, there were 75 MBC and 1,313 FBC totaling 1,388 breast cancers. The median age of the cohort was 53 (range: 23-90) years. Median follow-up was 90 (range: 0.4-339) months. Prognostic factors of patients were balanced among the groups after adjusting for propensity scores. A Cox model adjusting for propensity scores showed that overall survival (OS) (HR= 2.52 (1.65, 3.86), P<0.001) and distant disease recurrence-free survival (DDRFS) (HR= 2.39 (0.75, 3.04), P=0.003) were significantly different for MBC and FBC. Analyses that stratified by propensity score quintiles had similar findings: OS HR=2.41 (1.67, 3.47), P<0.001); DDRFS HR=2.89 (1.81, 4.60), P<0.001). When MBC and FBC were matched (1:3) by propensity scores, differences between MBC and FBC were again observed in OS (HR=1.94, 95%CI:1.18-3.19, P=0.009) and DDRFS (HR=2.79, 95%CI:1.36-5.75, P=0.005) with MBC at a higher risk of death and  disease recurrence compared to FBC . CONCLUSION: This large series showed that MBC and FBC survivals are not similar, with MBC having a worse outcome. The finding of this study needs confirmation from a complete prospective database.

Diagnosis and Management of Spinal Metastasis of Glioblastoma.

BACKGROUND: When patients with cranial glioblastoma develop weakness, a rare differential diagnosis is spinal metastases. METHODS: Chart and literature reviews were performed. RESULTS: The reported patient had delayed onset spinal drop metastasis that was only detected by magnetic resonance imaging (MRI). A 48-year-old patient had supratentorial glioblastoma, treated with radiotherapy (RT) and concurrent temozolomide followed by six cycles of adjuvant temozolomide. Four years after completion of all treatments (62 months from initial presentation), he developed low backache and weakness in both legs. Positron emission tomography/computed tomography scans demonstrated intracranial recurrence only. Spinal drop metastases were detected only by MRI scan. Local spinal RT 40 Gy in 20 fractions with concurrent and maintenance temozolomide were given. Because of disease progression after nine cycles of temozolomide, systemic therapy was changed to bevacizumab, which greatly improved his symptoms for 4 months before deterioration of mental status. He is still alive with disease at 22 months after diagnosis of spinal metastases (84 months from initial glioblastoma diagnosis). CONCLUSIONS: MRI is the diagnostic imaging of choice for spinal metastases. This illustrative case of delayed-onset spinal metastases shows unusual slow progression. Local RT, temozolomide, and targeted therapy may improve survival. This illustrative case is the first report of bevacizumab as a second-line therapy in drop metastasis of glioblastoma.

Overall Quality of Life Assessment in the Patients Undergoing External Beam Radiation in Outpatient Radiation Oncology Department.

BACKGROUND: The impact of treatment on cancer patients' quality of life (QoL) has been the focus of a variety of longitudinal studies in English literature for past decade. The measurement of patient-reported outcomes which includes health-related quality of life is a new important initiative which has emerged and grown over the past three decades. Following the development of reliable and valid self-reported questionnaires, health-related quality of life has been assessed in tens of thousands of patients and a wide variety of cancers. With growing information, feedback and experience, the quality of the health-related QOL studies has improved a lot. We expect in near future more methodologically robust studies will be done in a scientific way to answer unanswered questions. METHODS: As part of a Dean's summer project, a survey was undertaken to facilitate a more complete description of the quality of life experience in patients with histological diagnosis of cancer undergoing external beam radiation as an outpatient at Allan Blair Cancer Center, Regina, Canada. The questionnaires had two major components: depression and global QOL. The depression was measured by the Zung Self-Rating Depression Scale which is a short self-administered survey to quantify the depression status of a patient. RESULTS: Overall, only the equation associated with the outcome of QoL - Physical well-being was significant. That data indicated that only the variable of age was a significant predictor. A positive relationship was present indicating higher levels of depression when patients received chemotherapy or narcotics. Breast cancer patients were less depressed than lung cancer patients. CONCLUSION: Cancer and its related treatment is an important health issue influencing QoL. The study has revealed that the use of chemotherapy and narcotics has a significant impact on the quality of life (QoL).

Radiation-induced second malignancies.

BACKGROUND: The number of patients with second malignancies is growing and they represent about one in six out of all new cancers. Second malignancies can be categorized into three major groups according to the predominant etiological factor(s): (i) treatment-related, (ii) part of a syndrome and (iii) those due to shared etiologic exposures. PATIENTS AND METHODS: This article focuses on radiation-induced malignancies with illustrative cases of thyroid, rectal cancer and sarcoma. RESULTS: The detection and management of radiation-induced malignancies of some case scenarios are presented. Second malignancies are detected within previous radiation field and the time intervals from previous tumor vary from 8 to 21 years. CONCLUSION: Clinicians should aim to reduce radiation-induced malignancies by careful selection of patients and radiation techniques before radiotherapy. Subsequent vigilant follow-up and investigations can detect these radiation-induced malignancies early and, hence, result in successful treatment.

A Simplified Supine Technique Expedites the Delivery of Effective Craniospinal Radiation to Medulloblastoma - Comparison with Other Techniques in the Literature.

A 28-year-old man presented to the emergency room with a severe headache of one day's duration. A computerized tomography scan showed a hemorrhagic tumor measuring 3.9 x 4.4 cm in the left cerebellar hemisphere. The resection specimen revealed medulloblastoma. He had two episodes of rebleeding and multiple postoperative issues preventing the use of prone craniospinal radiotherapy. We designed a supine technique for this tall man, which was not complicated to set up. The rapid safe implementation of this technique allowed us to avoid further rebleeding and successfully treat the residual tumor. This technique is the described technique in this case report and is compared to other techniques. At 7.5 years after surgery, he is alive without cancer and with only a mild residual deficit. This case is unusual since the majority of patients with the diagnosis of hemorrhagic medulloblastoma died.

Carcinoma of unknown primary in the inguinal lymph node region of squamous cell origin: A case series.

PURPOSE: Cancer of unknown primary (CUP) of the inguinal region is a rare clinical entity that accounts for 1%-3 % of all CUPs. Of the inguinal lymph node region CUPs, about 10%-15% are of squamous cell origin. This study presents a case series of CUP of the inguinal region of squamous cell origin treated in our institution and review of the outcome. METHODS AND MATERIALS: We have identified 9 patients treated during the period of 1990-2010. All patients were treated radically with chemoradiation. Regimens used were 5-fluorouracil (5-FU)/cisplatin combination (n = 8) or 5-FU/mitomycin-C (n = 1) regimen. Tumor doses were 5400 cGy (n = 7), 5500 cGy (n = 1), and 5040 cGy (n = 1). RESULTS: The median duration of follow-up was 56 months (range, 10-76 months) for the whole group. There were no deaths or local or distant recurrences reported till the last recorded date of follow-up. CONCLUSIONS: Our retrospective data showed significant long-term disease control for patients with localized inguinal region CUP of squamous cell origin who received concurrent chemoradiation.

Esophageal cancer management controversies: Radiation oncology point of view.

Esophageal cancer treatment has evolved from single modality to trimodality therapy. There are some controversies of the role, target volumes and dose of radiotherapy (RT) in the literature over decades. The present review focuses primarily on RT as part of the treatment modalities, and highlight on the RT volume and its dose in the management of esophageal cancer. The randomized adjuvant chemoradiation (CRT) trial, intergroup trial (INT 0116) enrolled 559 patients with resected adenocarcinoma of the stomach or gastroesophageal junction. They were randomly assigned to surgery plus postoperative CRT or surgery alone. Analyses show robust treatment benefit of adjuvant CRT in most subsets for postoperative CRT. The Chemoradiotherapy for Oesophageal Cancer Followed by Surgery Study (CROSS) used a lower RT dose of 41.4 Gray in 23 fractions with newer chemotherapeutic agents carboplatin and paclitaxel to achieve an excellent result. Target volume of external beam radiation therapy and its coverage have been in debate for years among radiation oncologists. Pre-operative and post-operative target volumes are designed to optimize for disease control. Esophageal brachytherapy is effective in the palliation of dysphagia, but should not be given concomitantly with chemotherapy or external beam RT. The role of brachytherapy in multimodality management requires further investigation. On-going studies of multidisciplinary treatment in locally advanced cancer include: ZTOG1201 trial (a phase II trial of neoadjuvant and adjuvant CRT) and QUINTETT (a phase III trial of neoadjuvant vs adjuvant therapy with quality of life analysis). These trials hopefully will shed more light on the future management of esophageal cancer.

Prognostic factors for male breast cancer: similarity to female counterparts.

AIM: To assess whether prognostic factors in male (MBC) and female (FBC) breast cancer have similar impact on survival. PATIENTS AND METHODS: Charts for men and women diagnosed with breast cancer referred to the London Regional Cancer Program (LRCP) were reviewed. Patients with distant metastatic diseases were excluded. Data on prognostic factors including age, nodal status, resection margin, use of hormonal therapy, chemotherapy with/without hormone and radiation therapy (RT), overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) were analyzed. Survival estimates were obtained using the Kaplan-Meier methodology. The Cox regression interaction was used to compare male and female differences in prognostic factors. RESULTS: From 1963-2006 there were 75 cases of MBC and 1,313 of FBC totaling in 1,388 breast cancer cases. The median age of the cohort was 53 (range=23-90) years. The median follow-up was 90 (range=0.4-339) months. Of the prognostic factors considered, nodal status had a significant Cox regression interaction. For OS, p=0.001 with hazard ratios of 0.83 (95% confidence interval CI=0.42-1.64) and 2.88 (95% CI=2.36-3.52) for males and females, respectively. For CSS p=0.041 with hazard ratios of 1.22 (95% CI=0.45-3.27) and 3.52 (95% CI=2.76-4.48) for males and females, respectively. For node-positive cases, distant disease recurrence-free survival was worse for MBC (log rank, p<0.001). CONCLUSION: This large series showed that the nodal status influences survival differently in MBC and FBC. The findings of this study need confirmation from a more complete prospective database and further investigations on improving high-risk node-positive MBC management are warranted.

A practical update of surgical management of merkel cell carcinoma of the skin.

The role of surgeons in the treatment of Merkel cell carcinoma (MCC) of the skin is reviewed, with respect to diagnosis and treatment. Most of the data in the literature are case reports. Surgery is the mainstay of treatment. A wide local excision, with sentinel node (SLN) biopsy, is the recommended treatment of choice. If SLN is involved, nodal dissection should be performed; unless patient is unfit, then regional radiotherapy can be given. Surgeons should always refer patients for assessment of the need for adjuvant treatments. Adjuvant radiotherapy is well tolerated and effective to minimize recurrence. Adjuvant chemotherapy may be considered for selected node-positive patients, as per National Comprehensive Cancer Network guideline. Data are insufficient to assess whether adjuvant chemotherapy improves survival. Recurrent disease should be treated by complete surgical resection if possible, followed by radiotherapy and possibly chemotherapy. Generally results of multimodality treatment for recurrent disease are better than lesser treatments. Future research should focus on newer chemotherapy and molecular targeted agents in the adjuvant setting and for gross disease.

Prophylactic cranial irradiation for patients with limited-stage small-cell lung cancer with response to chemoradiation.

BACKGROUND: Previous clinical studies have generally reported that prophylactic cranial irradiation (PCI) was given to patients with a complete response (CR) to chemotherapy and chest radiotherapy in limited-stage small-cell lung cancer (SCLC). It is not clear if those with incomplete response (IR) would benefit from PCI. PATIENTS AND METHODS: The Saskatchewan experience from 1981 through 2007 was reviewed. Patients were treated with chest radiotherapy and chemotherapy with or without PCI (typical doses: 2500 cGy in 10 fractions over 2 weeks, 3000 cGy in 15 fractions over 3 weeks, or 3000 cGy in 10 fractions over 2 weeks). RESULTS: There were 289 patients treated for curative intent, 177/289 (61.2%) of whom received PCI. For the whole group of 289 patients, PCI resulted in significant overall survival (OS) and cause-specific survival (CSS) benefit (P = .0011 and 0.0005, respectively). The time to symptoms of first recurrence at any site with or without PCI was significantly different: 16.9 vs. 13.2 months (P = .0006). PCI significantly delayed the time to symptoms of first recurrence in the brain: 20.7 vs. 10.6 months (P < .0001). The first site of metastasis was the brain for 12.5% and 45.5% patients with CR with and without PCI, respectively (P = .02) and in 6.1% and 27.6% of patients with IR with and without PCI, respectively (P = .05). For the 93 patients with IR, PCI did not confer OS or CSS benefit (P = .32 and 0.39, respectively). CONCLUSIONS: Patients with IR benefited from PCI, with a reduced rate of and a delayed time for the development of brain metastases, although without significant OS or CSS benefit. PCI could be considered for all patients with limited-stage SCLC responding to chemoradiation.

Luteinizing hormone-releasing hormone antagonists for urinary obstruction in prostate cancer.

Luteinizing hormone-releasing hormone (LHRH) antagonists rapidly reduce testosterone and are preferred to LHRH agonists in situations when early response is important. The lack of flare reaction, as compared to LHRH agonists, is particularly desirable as it would not aggravate the problem. A 78-year-old man presented with symptoms of urinary tract obstruction. He had a prostate-specific antigen (PSA) of 91.3 ug/L and serum creatinine 146 umol/L. He had a large pelvic mass due to histologically confirmed prostate cancer, resulting in moderate left hydronephrosis and deteriorating renal function (serum creatinine of 163 umol/L). He was started on combined degarelix and bicalutamide on the day of consultation (day 0). The hydronephrosis resolved on the repeat computerized tomography scan performed on day 10. Serum creatinine normalized to under 130 umol/L on day 18. The PSA fell to 11 ug/L on day 18, 2.8 ug/L on day 28, and 0.5 ug/L on day 53. Therefore, LHRH antagonists are particularly useful in urgent situations. It is the preferred choice in these circumstances.

Role of conservative (palliative) care-only in the management of advanced malignant pleural mesothelioma.

Despite new aggressive therapeutical options for advanced malignant pleural mesothelioma (MPM), benefits to survival remain limited. Moreover, deleterious effects of high-dose chemotherapy and aggressive surgery are well-known. Outcomes of untreated patients are usually not reported, and whether a treatment can be delayed or avoided is still an open question. We discuss here two clinical cases and with conservative (palliative) management alone for advanced MPM [corrected].

Long-term outcome of breast cancer patients with one to two nodes involved - application of nodal ratio.

Nodal ratio (NR) is defined as the number of involved nodes to the number of nodes examined. There is limited information on the application of NR on population data. Previous reports in breast cancer generally analyzed one to three positive axillary nodes as a single group. This study investigates whether one to three positive axillary nodes is a homogeneous group in prognosis by comparing one to two positive nodes to three positive nodes. The population-based registry of a Canadian province from 1981 through 1995 was searched. As the reliability of nodal assessment depends on the number of nodes sampled, we also studied the subgroup of patients with greater than or equal to eight nodes dissected. Of a total of 5,996 breast cancer patients, 1187 had one to three positive axillary nodes. The 263 patients with three positive nodes compared to the 924 patients with one to two nodes fared worse with a significantly reduced cause-specific survival (CSS) and overall survival (OS). Patients with one to two positive nodes had similar CSS (p=0.31) and OS (p=0.63). Among those with greater than or equal to eight nodes dissected, there were 677 patients with one to two positive nodes. CSS and OS were not significantly different between one versus two positive nodes (p=0.16 and 0.34, respectively), but with NR, the corresponding p values were 0.0068 and 0.08, respectively. The cutoff value of NR 0.15 was found to be most useful and confirmed by the validation dataset. NR is able to segregate patients better than the absolute number of positive nodes used in the current staging system. NR should be incorporated into the staging system.

Outcome analysis of breast cancer patients who declined evidence-based treatment.

BACKGROUND: To analyze the characteristics and outcomes of women with breast cancer in the Northern Alberta Health Region (NAHR) who declined recommended primary standard treatments. METHODS: A chart review was performed of breast cancer patients who refused recommended treatments during the period 1980 to 2006. A matched pair analysis was performed to compare the survival data between those who refused or received standard treatments. RESULTS: A total of 185 (1.2%) patients refused standard treatment. Eighty-seven (47%) were below the age of 75 at diagnosis. The majority of those who refused standard treatments were married (50.6%), 50 years or older (60.9%), and from the urban area (65.5%). The 5-year overall survival rates were 43.2% (95% CI: 32.0 to 54.4%) for those who refused standard treatments and 81.9% (95% CI: 76.9 to 86.9%) for those who received them. The corresponding values for the disease-specific survival were 46.2% (95% CI: 34.9 to 57.6%) vs. 84.7% (95% CI: 80.0 to 89.4%). CONCLUSIONS: Women who declined primary standard treatment had significantly worse survival than those who received standard treatments. There is no evidence to support using Complementary and Alternative Medicine (CAM) as primary cancer treatment.

Treatment outcomes in non-metastatic prostate cancer patients with ultra-high prostate-specific antigen.

PURPOSE: It is commonly believed that prostate cancer patients with very high prostate-specific antigen (PSA) levels are unlikely to benefit from definitive local treatment, and patients with very high PSA are often underrepresented in, or excluded from, randomized clinical trials. Consequently, little is known about their optimal treatment or prognosis. We performed a registry-based analysis of management and outcome in this population of patients. METHODS AND MATERIALS: Our provincial Cancer Registry was used to identify all men who were diagnosed with prostate cancer from 1990 to 2001. A retrospective chart review provided information on stage, Gleason score, PSA at diagnosis, and treatment. In this study, ultra-high PSA was defined as PSA of ≥ 50 ng/ml. For a more complete perspective, treatment outcomes of patients with PSA of 20 to 49.9 ng/ml were also studied. RESULTS: Of the 8378 men diagnosed with prostate cancer during this period, 6,449 had no known nodal or distant metastatic disease. The median follow-up of this group was 67.2 months (range, 0-192 months). A total of 1534 patients had PSA of ≥ 20 ng/ml. Among the 995 patients with PSA 20 to 49.9 ng/ml, 85 had radical prostatectomy (RP), and their 5- and 10-year cause-specific survivals (CSS) were 95% and 84%, respectively. The 497 patients treated with radiotherapy (RT) had 5- and 10-year CSS of 92% and 71%. For the 332 patients with PSA 50-99.9 ng/ml, RT was associated with 5- and 10-year CSS of 81% and 55%. For the 207 patients with PSA of ≥ 100 ng/ml, RT was associated with 5- and 10-year CSS of 80% and 54%. CONCLUSIONS: This is the largest series in the world on non metastatic cancer patients with ultra-high PSA at diagnosis. Even in the setting of a very high presenting PSA level, prostatectomy and radiotherapy are often associated with prolonged survival.