Dramatic response to local radiotherapy in a refractory metastatic mediastinal yolk sac tumor patient harboring a germline BRCA2 frameshift mutation: a case report.

Mediastinal yolk sac tumors (YSTs) are highly aggressive germ cell tumors with an extremely poor prognosis. Radiotherapy plays an important role in the treatment of mediastinal YSTs. To maximize benefit from radiotherapy in patients with mediastinal YSTs, exploring functionally relevant biomarkers is essential. Previous studies have demonstrated that mutations in DNA-damage repair (DDR) genes, including BRCA1/2, potentially enhance sensitivity to radiotherapy in solid tumors. However, DDR-gene mutations, as possible predictive biomarkers for radiotherapy in primary mediastinal YSTs, have not yet been reported. Herein, we report a 29-year-old male patient with a refractory metastatic primary YST involving a germline frameshift mutation in the BRCA2 gene (NM_000059.3: exon11: c.4563_4564delAT: L1522fs). During treatment alternation, the patient was found to respond poorly to chemotherapy with or without an immune checkpoint inhibitor but well to radiotherapy. Finally, the patient achieved approximately 17 months of overall survival. To the best of our knowledge, this case report is the first to describe a remarkable response to local radiotherapy in a patient with a refractory metastatic mediastinal YST involving a DDR-gene mutation (germline BRCA2 frameshift variation). This case report provides insightful clues for precision radiotherapy in clinical practice.

Yolk Sac Tumor of the Temporal Lobe: Case Report

Germ cell tumors of the central nervous system (CNS) are usually located along the midline. Yolk sac tumor is a rare germ cell tumor very uncommonly located outside the midline, and, in such cases, it can be mistaken with other primary tumors. We report a case of a 32-year-old male patient who presented with a right temporal lobe tumor suggestive of a high grade glioma. He was submitted to a right temporal lobectomy with complete tumor removal. The histological exam revealed a germ cell tumor (later confirmed to be a yolk sac tumor). The search for a primary tumor outside of the CNS (including a positron emission tomography scan) was negative, making this a primary temporal lobe yolk sac tumor. The patient was submitted to chemotherapy and radiotherapy, but died 7 months after the surgery.

Intracranial yolk sac tumor in a patient with Down syndrome.

The authors report a rare case of intracranial yolk sac tumor in a 13-year-old boy with Down syndrome who presented with left hemiparesis. Admission MR imaging revealed a tumor in the right basal ganglia. Serum α-fetoprotein was markedly elevated. Yolk sac tumor was diagnosed radiologically and serologically. The standard therapy for intracranial yolk sac tumor is platinum-based chemotherapy with concomitant radiotherapy. However, the authors used reduced-dose chemotherapy and asynchronized radiotherapy because of the well-known low tolerance of patients with Down syndrome to chemotherapy. This treatment was successful with no complications. Blood cancers are frequently associated with Down syndrome, whereas solid tumors occur less frequently in these patients, and the risk of chemoradiotherapy is unclear. The results indicate that dose-reduction therapy can be effective for treatment of a brain tumor in a patient with Down syndrome.

[Sigmoid colon cancer in a woman developing 22 years after radiation therapy for a yolk sac tumor].

A 34-year-old woman was referred to our hospital with ileus. She had undergone surgical resection following chemotherapy for yolk sac tumor at the age of 12 years, and had received additional surgery and radiation therapy for a local recurrence at age 13. Following evaluation, a sigmoid colon tumor was detected and was surgically resected. Histology proved well differentiated adenocarcinoma with chronic irradiation colitis, suggesting that irradiation may have induced the colon cancer.

Lung fibrosis 10 years after cessation of bleomycin therapy.

Bleomycin (BLM) is a chemotherapeutic agent used for the treatment of several types of malignancy, including germ cell tumors, lymphoma, and certain types of squamous-cell carcinoma. The common adverse effect of BLM is interstitial pneumonitis, followed by pulmonary fibrosis. BLM-induced pneumonitis occurs in up to 46% of patients treated with BLM-containing chemotherapy and lung toxicity usually appears during treatment. Here we describe a patient with lung fibrosis, who presented with slow progressive breathlessness and pneumothorax more than 10 years after cessation of BLM therapy. A 15 year-old girl presented with abnormal shadows on chest X-ray. The patient had a yolk sac carcinoma in the sacral region at 1 year of age and obtained complete remission after being treated with tumor resection, radiation, and several anti-cancer drugs including BLM. There were no abnormal findings in chest X-ray until she reached 3 years of age, when she had developed respiratory distress that worsened with age. The patient had experienced an episode of pneumothorax at 13 years of age. Chest CT at the time revealed interstitial reticular opacities. Radiological findings and pathological examination of the lung tissue obtained during bullectomy with video-assisted thoracic surgery were compatible with BLM-induced pneumonitis. The present study suggests that lung fibrosis may surface more than 10 years after cessation of BLM therapy at the age of 1 year, with no chest radiographic findings 1 year after completion of chemotherapy. The use of BLM in infants requires strict supervision and observation and careful long-term follow up.

Treatment of a pineal yolk sac tumor: report of one case.

Pineal yolk sac tumors are rare. We present a case of pineal yolk sac tumor in a 15-year-old boy with hydrocephalus and possible cerebrospinal dissemination. He was treated by surgical excision, craniospinal axis irradiation, PVBE (cisplatin, vinblastine, bleomycin, and etoposide) chemotherapy, and intrathecal methotrexate chemotherapy. There was no tumor recurrence at follow-up 2.5 years after treatment.

Interaction of radiation and etoposide on two cell lines with different radiosensitivities in vitro.

PURPOSE: To investigate the differences between two rat yolk sac tumor cell lines with different radiosensitivities in etoposide sensitivity and in the sensitizing effect of etoposide in combination with irradiation. MATERIALS AND METHODS: NMT-1 is a parent radiosensitive cell line and NMT-1R is a variant radioresistant cell line. The effects were assessed by clonogenic assay. Apoptosis was evaluated by DNA fragmentation to investigate the mechanism of cell death. RESULTS: Etoposide potentiation of radiation sensitivity was manifested by elimination of the initial shoulder of the cell survival curve in radioresistant NMT-1R cells. However, there was no enhancement effect in radiosensitive NMT-1 cells. The incidence of apoptosis was elevated in NMT-1R cells treated with etoposide and radiation. CONCLUSION: Etoposide had a supra-additive effect in combination with irradiation for radioresistant NMT-1R cells due to the induction of apoptosis. However, a suppra-additive effect was not seen in radiosensitive NMT-1 cells.

Successful treatment of intracranial nongerminomatous malignant germ cell tumors by administering neoadjuvant chemotherapy and radiotherapy before excision of residual tumors.

OBJECT: The goal of this study was to confirm the effectiveness of our novel treatment strategy, neoadjuvant therapy (NAT) consisting of combined chemo- and radiotherapy, which are performed before complete excision of residual tumor in patients with intracranial nongerminomatous malignant germ cell tumors (NGMGCTs). METHODS: The authors treated 11 consecutive patients with NGMGCTs by applying NAT consisting of combined platinum-based chemotherapy and radiotherapy, followed by complete excision of residual tumors. The pretreatment diagnosis, based on tumor markers with or without biopsy, was yolk sac tumor in five patients, embryonal carcinoma in one patient, immature teratoma in one patient, and mixed germ cell tumor containing malignant tumor components in four patients. Among the 11 patients, NAT achieved a complete response in two and a partial response in six patients; two patients manifested no change and one suffered disease progression. Residual tumors that occurred post-NAT were surgically removed in nine patients. Of the 11 patients, 10 are currently alive without recurrence of their disease, 30 to 177 months (mean 96 months) after diagnosis. In one patient a leptomeningeal tumor recurred and he died of the disease 21 months after diagnosis. CONCLUSIONS: Neoadjuvant therapy, consisting of combined chemo- and radiotherapy, followed by complete excision of residual tumors is highly effective in patients with intracranial NGMGCTs.

Combined effect of hyperthermia at 42 degrees C and irradiation dose of 2 Gy on two rat yolk sac tumor cell lines with different radio-thermosensitivity in vitro.

BACKGROUND: Two rat yolk sac tumor cell lines, NMT-1 and NMT-1R, are of the same origin and of different sensitivity to irradiation and to heat. The aim of this study was to investigate the sensitivities of these two cell lines to combined treatments of low-dose irradiation at 2 Gy and hyperthermia at 42 degrees C. MATERIALS AND METHODS: The cell survival was assayed by soft agar clonogenic assay. After the survival curves of radiation alone and of heat alone at various temperatures were estimated, not only the effect of irradiation on heat, but the effect of heat on irradiation were evaluated with sequential treatments in both cell lines. These effects on survival curves were evaluated by the enhancement ratios at isosurvival levels of 37%, 10% and 1%, respectively. RESULTS: NMT-1 was more sensitive to radiation but more resistant to heat than NMT-1R. For 1% survival level, radiosensitivity in NMT-1 was 1.32 times that in NMT-1R, while thermal sensitivity at 42 degrees C in NMT-1R was 2.73 times that in NMT-1. For sequential treatment, thermosensitization by a radiation dose of 2 Gy in radiosensitive NMT-1 was greater than that in radioresistant NMT-1R. Following heat at 42 degrees C for 1 hour, increased radiosensitivity in NMT-1R was significant, whereas the same heat treatment produced an increase in the radiation sensitivity of NMT-1 with a reduction of the survival curve shoulder but with less slope modification. There was no difference in the surviving fraction in the time-course of a combination of heat and irradiation at various intervals within 6 hours for NMT-1 except for heating immediately after irradiation. However a significant increase in survival was observed when heat was applied more than 3 hours after 2 Gy irradiation for NMT1-R. CONCLUSION: These results from our cell lines with the same origin were useful for investigation into the interaction of irradiation with heat.

The effects on teeth of radiotherapy for nasal endodermal sinus tumor (yolk sac tumor) in childhood.

A rare case of a 10-year-old girl with an endodermal sinus tumor that occurred in the nasal cavity is presented. She received chemotherapy and radiotherapy at the age of 4. The subsequent abnormal development of the maxillary teeth is described and discussed in the light of the known effects of radiotherapy.

Hyperthermia-induced apoptosis in two rat yolk sac tumor cell lines with different radiothermosensitivity in vitro.

We investigated cell susceptibility to hyperthermia-induced apoptosis in two rat yolk sac tumor cell lines (RYSTs) and attempted to correlate this with the known potentially relevant molecular determinants of apoptosis, p53 protein status, Bcl-2 family of proteins and heat shock proteins (Hsp). Parent cell line, NMT-1 (carrying wild-type p53 gene) was radiosensitive but thermoresistant compared to the variant cell line, NMT-1R (mutated type p53), which was isolated from NMT-1 by repeated radiation exposure. Induction of apoptosis by hyperthermia at 43 degrees C was morphologically detected in both RYSTs using hematoxylin and eosin, and TUNEL staining and additionally confirmed by DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments). Western blot analysis showed an increase in expression of p53, p21WAF1/CIP1, Hsp70 proteins in both cell lines after heat-shock at 43 degrees C for 30 min. Hsp90 expression increased in NMT-1 but was not affected by heating in NMT-1R cells, whereas hyperthermia exerted no effect on the endogenous expression of Bax. Bcl-2 protein could not be detected in either RYST. These results suggest that hyperthermia induced apoptosis in both NMT-1 and NMT-1R and apoptosis in RYSTs may be independent of p53-dependent signaling pathway.

Caffeine enhanced radiosensitivity of rat tumor cells with a mutant-type p53 by inducing apoptosis in a p53-independent manner.

The radiosensitizing effects of caffeine on two rat yolk sac tumor cell lines with a different p53 status were investigated. A reduction of radiation-induced G(2) arrest was caused by caffeine at a concentration of 2 mM in both cell lines. The reduction of survival was observed in a combination of radiation and 2 mM caffeine only in a lower radiation dose range, but not in a higher dose range in NMT-1 with a wild type p53. Radiosensitization of caffeine was recognized even in a higher dose range for cells with a mutant-type p53. Apoptosis, which was not prominent after irradiation alone or caffeine treatment alone, was induced by irradiation in combination with caffeine in cells with a mutant-type p53 through a p53-independent pathway.

Preliminary observations for a new treatment in children with primary intracranial yolk sac tumor or embryonal carcinoma. Report of five cases.

The authors evaluated the effect of adjuvant therapy (preoperative chemotherapy combined with radiotherapy) followed by radical tumor removal in the treatment of children with primary intracranial yolk sac tumor, embryonal carcinoma, or mixed germ cell tumors containing yolk sac tumor components. Between 1988 and 1995, five consecutive patients were treated with adjuvant therapy followed by total tumor removal. The diagnosis was based on markedly elevated concentrations of serum alpha-fetoprotein (AFP) and/or beta-human chorionic gonadotropin (beta-HCG) in four children and the results of biopsy sampling in one child. The chemotherapy regimen consisted of cisplatin (20 mg/m2) and etoposide (60 mg/m2) daily for 5 days (one course) given three times at 4-weeks intervals. Radiotherapy consisted of 30 to 40 Gy to the whole brain or an area including all ventricles and a 15- to 20-Gy boost to the tumor site. Spinal radiation of 25 Gy was added in one patient. In all patients the serum level of AFP and beta-HCG gradually decreased during the adjuvant therapy and disappeared completely on its completion. In two of the five patients the tumor disappeared as well. In the other three patients the tumor size was moderately or markedly reduced and the remaining tumor was totally removed; there were no neurological deficits. Chemotherapy was maintained after the initial treatment and was repeated every 2 to 4 months for less than 2 years. All children are alive and well without recurrence at 33 to 118 months (average 88 months) after the start of adjuvant therapy. Our preliminary results indicate that adjuvant therapy consisting of combination chemotherapy with cisplatin and etoposide and concomitant radiotherapy, followed by removal of the tumor, is highly effective in the treatment of pediatric patients with primary intracranial yolk sac tumor, embryonal carcinoma, or mixed germ cell tumors containing yolk sac tumor components.

Potentially lethal damage repair and its inhibitory effect of caffeine in two yolk sac tumor cell lines with different radiosensitivities.

PURPOSE: In order to investigate the role of potentially lethal damage repair (PLDR) in cellular radiosensitivity, PLDR and its inhibitory effect by caffeine was examined. In addition, cell cycle distribution was also examined. MATERIALS AND METHODS: Two rat yolk sac tumor cell lines, NMT-1 and NMT-1R, with different radiosensitivities in vitro were used. The capacity for PLDR was examined using confluent-phase cells, and evaluated by calculating the recovery ratio. Inhibitory effect of caffeine on PLDR was examined with doses of 1, 5 and 10 mM. RESULTS: The capacity of PLDR in two cell lines reflected radiosensitivity. The recovery ratio after irradiation of 5 Gy was 2.8 in the radiosensitive NMT-1 and 5.2 in the radioresistant NMT-1R, and recovery reached its peak level at 6 h in both cell lines. The degree of inhibition of PLDR was weaker in NMT-1R than that in NMT-1 at the same dose level, and was correlated with reduction of G2-arrested cells by caffeine. CONCLUSIONS: The results of this study suggest that the capacity of PLDR may be one of the determinant factors for radiosensitivity in the two cell lines used, and the inhibitory effect of caffeine on PLDR was in part attributable to the modification of the cell cycle progression.

[Gastrocystoplasty for severely contracted bladder following high dose pelvic irradiation: a case report].

A 24-year-old female who had received hysterectomy and adnexectomy of bilateral appendages for yolk sac tumor at the age of 12 years, followed by repeated surgery and pelvic irradiation over a total of 100 Gy for relapse of tumor, suffered from a severely contracted bladder and renal dysfunction of serum creatinine level over 2.0 mg/dl. The diagnosis was radiation-induced contracted bladder with renal dysfunction due to vesicoureteral reflux. Since the small intestine was not considered suitable after high dose irradiation, the stomach was used to reconstruct the bladder. The vesical pressure, which was 70 cmH2O at the capacity of 30 ml, was decreased to 22 cmH2O at the capacity of 100 ml, 5 weeks after surgery. The renal function was stable with a serum creatinine level below 1.4 mg/dl and the bladder capacity was 200 ml, 15 months after surgery. This method using the stomach was considered valuable for bladder reconstruction after large dose pelvic irradiation.

Cytotoxic effect of paclitaxel (taxol) either alone or in combination with irradiation in two rat yolk sac tumour cell lines with different radiosensitivities in vitro.

PURPOSE: To investigate the differences between two rat yolk sac tumour cell lines with different radiosensitivities in paclitaxel sensitivity and in the sensitizing effects of paclitaxel in combination with irradiation. MATERIALS AND METHODS: NMT-1 is a parent radiosensitive cell line and NMT-1R is a variant radioresistant cell line. RESULTS: Clonogenic assay demonstrated almost the same paclitaxel sensitivity with Do of 5.15 nM in NMT-1 and 5.02 nM in NMT-1R. Many apoptotic cells and DNA ladder formations were observed at 24 h after exposure to paclitaxel in both cell lines. The incidence of DNA fragmentation after 24 h exposure to 20 nM paclitaxel was 12.4 +/- 3.3% for NMT-1, and 13.0 +/- 1.9% for NMT-1R. Paclitaxel showed a supra-additive effect in combination with irradiation in both cell lines at 12 h after paclitaxel treatment only when the accumulation of cells in the G2/M phase reached its peak. CONCLUSIONS: Paclitaxel had the same cytotoxic effect in two cell lines with different radiosensitivity due to the induction of apoptosis. A supra-additive effect to radiation was observed with 12 h pretreatment in both cell lines. Paclitaxel may be effective for tumours with a component of different radiosensitivity in combination with irradiation.

A quantitative study of radiation-induced apoptosis in two rat yolk sac tumour cell lines with different radiosensitivities in vitro.

Two rat yolk sac tumour cell lines with different radiosensitivities were used to quantify the extent of apoptosis following irradiation by using a DNA fragmentation assay in vitro. Apoptosis was also confirmed by fluorescence analysis of nuclear morphological changes by using Hoechst 33258. A radiosensitive cell line, NMT-1 cells, showed morphological changes characteristic of apoptosis by fluorescence microscopic observation at 24 hours after irradiation with a single dose of 10 Gy. Development of apoptosis in NMT-1 cells was observed as a function of time within 24 hours after irradiation. There was a significant increase in the amount of apoptosis between 2 and 5 Gy only in NMT-1 cells but increasing the radiation dose from 5 Gy to 10 Gy did not result in increased apoptosis. A radioresistant NMT-1R cells, on the other hand, displayed a small apoptotic response to an irradiation dose of 10 Gy at 24 hours after irradiation.

An interaction of cisplatin and radiation in two rat yolk sac tumour cell lines with different radiosensitivities in vitro.

We investigated the interaction of cisplatin and radiation in two rat yolk sac tumour cell lines with different radiosensitivities in vitro. The effects were assessed by clonogenic assay. D0 for the radiosensitivity of the radioresistant variant cell line, NMT-1R was 139 cGy, which was 1.3 times larger than that for the parent radiosensitive cell line, NMT-1 (D0 = 107 cGy). The concentration of cisplatin required to reduce colony formation by 50% at 1 h treatment (ID50 of cisplatin) was 0.25 microgram/ml for NMT-1, whereas that for NMT-1R was 1.0 microgram/ml. Cisplatin potentiation of radiation sensitivity was manifested by the decrease in the slope of the radiation dose-response curve. D0's for NMT-1 and NMT-1R were 83 and 100 cGy in combined treatment with ID50 of cisplatin immediately before radiation. The enhancement ratios of cisplatin were therefore 1.30 for NMT-1 and 1.39 for NMT-1R respectively in D0. No different enhancement ratio for cisplatin was observed in the time course of combination treatment with cisplatin and radiation within the interval of 6 h. There was no clear change in cell cycle distribution within 6 h after treatment with ID50 of cisplatin for both cell lines. In conclusion, cisplatin had a synergistic effect on both cell lines which was independent of the time course and sequence in combination with radiation within 6 h.

A radioresistant variant cell line, NMT-1R, isolated from a radiosensitive rat yolk sac tumour cell line, NMT-1: differences of early radiation-induced morphological changes, especially apoptosis.

A radioresistant variant cell line, NMT-1R, was isolated by repeated radiation exposure of a radiosensitive rat yolk sac tumour cell line, NMT-1, producing alpha-fetoprotein, with the potential for lymphatic metastasis in the inbred Wistar rat. Cultured NMT-1R cells showed more cobblestone-like appearances, although the morphological features were almost the same as radiosensitive NMT-1 cells reported previously. The doubling time of NMT-1R cells was 13.6 h, being shorter than that of NMT-1 cells (16.0 h). For NMT-1R cells, D0 for radiation sensitivity was 165 +/- 3 cGy, 1.7 times as large as for NMT-1 cells. The extrapolation number, n, was 1.48 +/- 0.17 for NMT-1R cells although that for NMT-1 cells was 1.08 +/- 0.15. The surviving fractions at 2 Gy (SF2) were 0.42 for NMT-1R cells and 0.28 for NMT-1 cells. The population of G2-M phase for NMT-1R cells was larger than for NMT-1 cells (32.5 versus 26.8%) in exponentially growing cells. Although a clear G2 delay was observed after irradiation with a dose of 182 cGy for both cell lines, NMT-1R cells had a shorter recovery time from G2 block than NMT-1 cells, G1 arrest was observed in NMT-1 cells. NMT-1 cells showed much higher incidence of early morphological changes, especially apoptosis, after irradiation with a dose > 500 cGy compared with NMT-1R cells.