Loperamide potentiates doxorubicin sensitivity in triple-negative breast cancer cells by targeting MDR1 and JNK and suppressing mTOR and Bcl-2: In vitro and molecular docking study.

Multidrug resistance (MDR) is the leading cause of treatment failure in triple-negative breast cancer (TNBC) patients treated with doxorubicin (DXR). We aimed to investigate the potential of the antidiarrheal drug Loperamide (LPR) in sensitizing TNBC cells to DXR and elucidate the underlying molecular mechanisms. Therefore, we examined the effects of DXR alone or in combination with LPR on MDA-MD-231 cells viability using MTT assay, cell cycle, and apoptosis by flow cytometry, and the expression of the MDR-related genes (MDR1 and JNK1) and cell cycle/survival genes (p21, mTOR, and Bcl-2) by quantitative reverse transcription polymerase chain reaction. Results showed that adding LPR to DXR potentiated its antiproliferation effect and reduced its IC50 by twofolds compared with DXR alone. The value of the combination index of LPR/DXR was <1 indicating a synergistic effect. Combined DXR/LPR treatment also caused G1 arrest and potentiated apoptosis more than DXR-single treatment. At the molecular levels, LPR/DXR treatment downregulated the mRNA of MDR1 (1.35-folds), JNK1 (2.5-folds), mTOR (6.6-folds), Bcl-2 (9.5-folds); while upregulated p21 gene (8-folds) compared with DXR alone. Molecular docking analyses found LPR antagonizes MDR1 and JNK1 proteins, and hence supports the in vitro studies. In conclusion, the results confirmed the potential of LPR in sensitizing TNBCs to DXR by targeting MDR1 and JNK1 and suppressing Bcl-2 and mTOR genes, while upregulating the cell cycle inhibitor gene p21. Additionally, LPR could be repurposed to reduce the therapeutic doses of DXR as indicated by the dose reduction index (DRI) and subsequently decrease its side effects.

Empagliflozin and Doxorubicin Synergistically Inhibit the Survival of Triple-Negative Breast Cancer Cells via Interfering with the mTOR Pathway and Inhibition of Calmodulin: In Vitro and Molecular Docking Studies.

Triple-negative breast cancers (TNBCs) comprise 10-15% of all breast cancers but with more resistance affinity against chemotherapeutics. Although doxorubicin (DOX) is the recommended first choice, it has observed cardiotoxicity together with apparent drug resistance. The anti-hyperglycemic drug, empagliflozin (EMP), was recently indicated to have in vitro anticancer potential together with its previously reported cardioprotective properties related to calmodulin inhibition. In this study, we carried out molecular docking studies which revealed the potential blocking of the calmodulin receptor by EMP through its binding with similar crucial amino acids compared to its cocrystallized inhibitor (AAA) as a proposed mechanism of action. Moreover, combination of DOX with EMP showed a slightly lower cytotoxic activity against the MDA-MB-231 cell line (IC50 = 1.700 ± 0.121) compared to DOX alone (IC50 = 1.230 ± 0.131), but it achieved a more characteristic arrest in the growth of cells by 4.67-fold more than DOX alone (with only 3.27-fold) in comparison to the control as determined by cell cycle analysis, and at the same time reached an increase in the total apoptosis percentage from 27.05- to 29.22-fold, compared to DOX alone as indicated by Annexin V-FITC apoptosis assay. Briefly, the aforementioned in vitro studies in addition to PCR of pro- and antiapoptotic genes (mTOR, p21, JNK, Bcl2, and MDR1) suggest the chemosensitization effect of EMP combination with DOX which can reduce the required therapeutic dose of DOX in TNBC and eventually will decrease its toxic side effects (especially cardiotoxicity), along with decreasing the chemoresistance of TNBC cells to DOX treatment.

Benefit of re-operation and salvage therapies for recurrent glioblastoma multiforme: results from a single institution.

The optimal management of recurrent glioblastoma (GBM) has yet to be determined. We aim to assess the benefits of re-operation and salvage therapies (chemotherapy and/or re-irradiation) for recurrent GBM and to identify prognostic factors associated with better survival. All patients who underwent surgery for GBM between January 2005 and December 2012 followed by adjuvant radiotherapy, and who developed GBM recurrence on imaging were included in this retrospective study. Univariate and multivariate analysis was performed using Cox models in order to identify factors associated with overall survival (OS). One hundred and eighty patients treated to a dose of 60 Gy were diagnosed with recurrent GBM. At a median follow-up time of 6.2 months, the median survival (MS) from time of recurrence was 6.6 months. Sixty-nine patients underwent repeat surgery for recurrence based on imaging. To establish the benefits of repeat surgery and salvage therapies, 68 patients who underwent repeat surgery were matched to patients who did not based on extent of initial resection and presence of subventricular zone involvement at recurrence. MS for patients who underwent re-operation was 9.6 months, compared to 5.3 months for patients who did not have repeat surgery (p < 0.0001). Multivariate analysis in the matched pairs confirmed that repeat surgery with the addition of other salvage treatment can significantly affect patient outcome (HR 0.53). Re-operation with additional salvage therapies for recurrent GBM provides survival prolongation at the time of progression.

Consent to external-beam radiotherapy.

Canadian law, and the physician's code of ethics, requires that informed consent be obtained before any medical act is performed. However, there are no rules about how consent is to be obtained and by whom, and how that consent is to be documented.In April 2008, we asked the heads of all Canadian radiation oncology departments to tell us whether their centre uses a written consent form for external-beam radiotherapy and, if it did, to send us a copy of the form or forms used. Responses were received from 29 of the 38 centres contacted (76%). In 12 centres, all of them in British Columbia or Quebec, no written consent is obtained. Of the 17 centres (59%) that do seek written consent, 9 use a generic hospital or cancer centre form. Only 5 use a form specific to radiotherapy that mentions multiple visits, photographs in the treatment position, use of tattoos, and so on, and only 2 use a form that is specific to the tumour type or site irradiated and that explains the risks associated with treatment. The final centre of the 17 did not provide a form for review.While current practice at the McGill University Health Centre is not out of line with that at other Canadian centres, the results of our survey suggest a need for dialogue on the subject of consent for external-beam radiotherapy.

Fractionated stereotactic radiotherapy in the treatment of pituitary macroadenomas.

BACKGROUND: The use of fractionated stereotactic radiotherapy (FSRT) has evolved with technical advances in noninvasive immobilization, radiation delivery, and image guidance. The application of FSRT to pituitary tumours is aimed at reducing toxicity through improved dose conformality and reduced treatment margins. The aim of the present paper is to report our own experience and to review the published data on FSRT for pituitary macroadenomas. METHODS: Between September 2000 and October 2005, 13 patients with pituitary macroadenoma underwent FSRT at our institution. In 12 patients, radiotherapy treatment followed surgical resection (transsphenoidal resection in 8, frontal craniotomy in 3, and multiple transsphenoidal resections followed by craniotomy in 1). In 4 patients, the tumours were functional (2 adrenocorticotropic hormone-secreting, 1 prolactinoma, and 1 growth hormone-secreting); the tumours in the remaining patients were clinically non-secretory. Before radiation, 3 patients had panhypopituitarism, and 6 patients had visual field defects. All patients were treated with FSRT using non-coplanar micro-multileaf collimation portals. A median dose of 50.4 Gy (range: 45-60 Gy) was prescribed to the 76.9%-95.2% isodose surface and delivered in 1.8-Gy fractions. The median planning target volume (gross tumour plus 3 mm) was 33.5 cm3 (range: 3.2-75 cm3). RESULTS: After a median follow-up of 24 months (range: 6-60 months), local control was 100%. One patient achieved clinical complete response. Treatment was well tolerated acutely for all patients. Neither radiation-induced optic neuropathy nor any radiation-related endocrine dysfunction was observed in our patients. CONCLUSIONS: In accordance with published series, we found FSRT to be safe and effective in the management of large pituitary macroadenomas.

Erythropoietin receptor expression in biopsy specimens from patients with uterine cervix squamous cell carcinoma.

Hypoxia, an important mechanism of radioresistance, is a strong stimulus for erythropoietin (EPO) production. The stimulatory effects of EPO are mediated through the activation of its receptors, EPO receptors (EPORs). The objective of this study is to determine whether EPORs are expressed in biopsy specimens of patients with squamous cell carcinoma of the cervix. Eighteen biopsy specimens were studied after obtaining Institutional Review Board-approved consent. Standard immunohistochemistry techniques were utilized. Expression of EPORs was present in 16 out of 18 (88.9%) specimens. The intensity (qualitative) and the frequency (semiquantitative) of EPORs expression showed a statistically significant correlation (P= 0.00379). Statistical analysis was performed to determine whether EPORs expression is related to other parameters such as age, FIGO stage, histologic grade, and hemoglobin levels. Only age showed a statistically significant correlation with EPORs frequency of expression (P= 0.00878). Currently, work is in progress in our laboratory to study the radiobiologic effects of EPO on the radiation response of cultured cancer cell lines in vitro.

Impact of geometric uncertainties on dose distribution during intensity modulated radiotherapy of head-and-neck cancer: the need for a planning target volume and a planning organ-at-risk volume.

We assessed the effect of geometric uncertainties on target coverage and on dose to the organs at risk (OARS) during intensity-modulated radiotherapy (IMRT) for head-and-neck cancer, and we estimated the required margins for the planning target volume (PTV) and the planning organ-at-risk volume (PRV). For eight head-and-neck cancer patients, we generated IMRT plans with localization uncertainty margins of 0 mm, 2.5 mm, and 5.0 mm. The beam intensities were then applied on repeat computed tomography (CT) scans obtained weekly during treatment, and dose distributions were recalculated.The dose-volume histogram analysis for the repeat ct scans showed that target coverage was adequate (V(100) >/= 95%) for only 12.5% of the gross tumour volumes, 54.3% of the upper-neck clinical target volumes (CTVS), and 27.4% of the lower-neck CTVS when no margins were added for PTV. The use of 2.5-mm and 5.0-mm margins significantly improved target coverage, but the mean dose to the contralateral parotid increased from 25.9 Gy to 29.2 Gy. Maximum dose to the spinal cord was above limit in 57.7%, 34.6%, and 15.4% of cases when 0-mm, 2.5-mm, and 5.0-mm margins (respectively) were used for prv.Significant deviations from the prescribed dose can occur during IMRT treatment delivery for head-and-neck cancer. The use of 2.5-mm to 5.0-mm margins for PTV and PRV greatly reduces the risk of underdosing targets and of overdosing the spinal cord.

Ultrasound imaging for external-beam prostate treatment setup and dosimetric verification.

Ultrasound (US) image-guided patient positional verification was performed daily on four prostate cancer patients using the BAT system (NOMOS Corporation, CA). The BAT system has shown that the prostate can shift by as much as 1 cm from its intended position in any direction. Furthermore, the daily shifts measured by the BAT system were included into the treatment planning system to assess changes in prostate dose coverage. Dose volume histograms were used to compare the dosimetry between the ideal patient set-up situation (prostate always positioned correctly) and that taking all patient daily shifts into consideration. Daily patient shifts on the order of magnitudes measured, can significantly and adversely affect dosimetric coverage, therefore an US-based patient positioning system is required for improving the therapeutic ratio.

New insights into the role of endothelin-1 in radiation-associated impotence.

The objectives of this work were to: (1) Determine if prostate and penile tissue levels of endothelin-1 (ET-1) are increased in a rat following pelvic irradiation. (2) Determine if an ETa receptor antagonist (BQ-123) potentiates erectile function in these irradiated animals. Rats were divided into three study groups: control, 1000 cGy and 2000 cGy. The experimental groups received a single dose of radiation to the pelvic region. A time course was established to measure the effects of irradiation on prostate and penile tissue levels of endothelin-1 (ET-1)-like immunoreactivity. The effect of intracavernous injection of BQ-123 (25 microg/30 microl) was evaluated by measuring intracavernous pressure (ICP) following cavernous nerve electrical field stimulation. In the 2000 cGy group, a significant rise in ET-1-like immunoreactivity tissue levels was observed at 20 days. A significant decrease in ICP was recorded in the 1000 and 2000 cGy irradiated rats compared to the control group. Only the 2000 cGy group had a significant improvement in erectile function following BQ-123 administration. A significant improvement was observed 20 min post-administration, lasted 90 min, and was back to pre-administered levels at 120 min. The conclusion made was that radiation-induced impotence in irradiated rats is associated with an increased production of ET-1. Preliminary results are suggestive that ETa receptor antagonist may be of use to reverse such radiation-induced impotence in these irradiated animals.

High dose tamoxifen and radiotherapy in patients with glioblastoma multiforme: a phase IB study.

PURPOSE: To assess the feasibility and the toxicity of adjuvant high dose tamoxifen (TAM) and postoperative brain irradiation for patients with newly-diagnosed glioblastoma multiforme (GBM). MATERIAL AND METHODS: Twelve patients with histopathologically confirmed GBM entered the study. There were nine males and three females, with median age of 48.8 years (range 30-75 years). Karnofsky performance status (KPS) was 60-70% for four patients and 80-100% for eight patients. Based on the Radiation Therapy Oncology Group recursive partition analysis, there were three class III patients, six class IV, one class V, and two class VI. Eleven patients underwent partial surgical tumor resection and one patient had a near complete resection. Two weeks post surgery, the patients were started on high dose TAM (120 mg/m2 P.O. BID for three months). Two weeks from date of starting TAM, external beam radiotherapy (RT) was given at a dose of 59.4 Gy/33 qd fractions/6.5 weeks. Patients were assessed weekly for toxicity during treatment. Imaging studies were done at the end of two weeks of TAM, then monthly. RESULTS: Median follow-up was 40 weeks (range 22-84 weeks). In one patient, TAM was associated with significant vomiting, necessitating the TAM dose to be decreased at three weeks and then stopped at two months. One other patient had bilateral deep venous thrombosis after 52 weeks on TAM, although the relationship to TAM was not firmly established. There were no radiological responses after two weeks of TAM or at the end of RT. The median time to progression was 17.7 weeks (range 5.1-43.8 weeks). Median survival time was 33.4 weeks (range 10-79.7). Actuarial survival at 48 and 74 weeks was 40% and 15%, respectively. CONCLUSION: Our study shows that adjuvant high dose TAM is feasible and relatively well-tolerated. Furthermore, the combined use of high dose TAM and RT postoperatively was not associated with any significant increase in radiation-induced neurological toxicity. However, high dose TAM does not appear to improve treatment results.

Using proton magnetic resonance spectroscopic imaging to predict in vivo the response of recurrent malignant gliomas to tamoxifen chemotherapy.

OBJECTIVE: Most patients with a malignant glioma spend considerable time on a treatment protocol before their response (or nonresponse) to the therapy can be determined. Because survival time in the absence of effective therapy is short, the ability to predict the potential chemosensitivity of individual brain tumors noninvasively would represent a significant advance in chemotherapy planning. METHODS: Using proton magnetic resonance spectroscopic imaging (1H MRSI), we studied 16 patients with a recurrent malignant glioma before and during treatment with high-dose orally administered tamoxifen. We evaluated whether 1H MRSI data could predict eventual therapeutic response to tamoxifen at the pretreatment and early treatment stages. RESULTS: Seven patients responded to tamoxifen therapy (three with glioblastomas multiforme; four with anaplastic astrocytomas), and nine did not (six with glioblastomas multiforme; three with anaplastic astrocytomas). Responders and nonresponders exhibited no differences in their age, sex, tumor type, mean tumor volume, mean Karnofsky scale score, mean number of weeks postradiotherapy, or mean amount of prior radiation exposure. Resonance profiles across the five metabolites measured on 1H MRSI spectra (choline-containing compounds, creatine and phosphocreatine, N-acetyl groups, lactate, and lipids) differed significantly between these two groups before and during treatment. Furthermore, linear discriminant analyses based on patients' in vivo biochemical information accurately predicted individual response to tamoxifen both before and at very early treatment stages (2 and 4 wk). Similar analyses based on patient sex, age, Karnofsky scale score, tumor type, and tumor volume could not reliably predict the response to tamoxifen treatment at the same time periods. CONCLUSION: It is possible to accurately predict the response of a tumor to tamoxifen on the basis of noninvasively acquired in vivo biochemical information. 1H MRSI has potential as a prognostic tool in the pharmacological treatment of recurrent malignant gliomas.

Occult cervical metastases: immunoperoxidase analysis of the pathologically negative neck.

OBJECTIVES: The purpose of this study is to better estimate the true incidence of occult regional metastases associated with stage I and II squamous cell carcinoma of the oral cavity. The clinical and prognostic significance of micrometastatic disease discovered by cytokeratin immunoperoxidase reactivity in the previously pathologically N0 neck is also evaluated. METHODS: Forty patients treated between 1985 and 1996 with T1 or T2 squamous cell carcinoma of the lip and oral cavity were studied. All had primary surgical treatment including functional neck dissection. No metastases were demonstrated on hematoxylin and eosin microscopy. All specimens were reexamined with immunoperoxidase staining for cytokeratin. RESULTS: Five percent of patients had micrometastatic disease. Retrospective analysis of patients with a minimum follow-up of 2 years has failed to show a statistically significant association between a positive cytokeratin analysis and poor locoregional control or overall survival. CONCLUSIONS: Results suggest that the true incidence of occult metastases with carcinoma of the oral cavity is significantly higher than previously documented. However, the prognostic significance of these findings remains unclear.

Overexpression of p53 protein does not predict local-regional control or survival in patients with early-stage squamous cell carcinoma of the glottic larynx treated with radiotherapy.

PURPOSE: Nonfunctional or mutated p53 protein (m-p53) is found in a myriad of solid tumors in humans. m-p53 is believed to confer radioresistance through inhibition of radiation-induced apoptosis. This study was carried out to determine if the overexpression of p53 in squamous cell carcinomas (SCC) of the glottic larynx treated with radiation therapy alone carried a poorer prognosis than normal wild-type p53 (w-p53) and could, therefore, be used as a marker of radioresistance in glottic SCC. METHODS & MATERIALS: Eighty-six patients with early-stage glottic SCC (64 T1N0, 25 T2N0 by TMN stage) treated with contemporary radiotherapy techniques to doses of 50-70 Gy were analyzed. Aberrant p53 protein was detected by immunohistochemical (IHC) staining on archival tissue samples containing original tumor specimens. Analysis of prognostic factors and treatment outcome to expression of p53 was performed. All patients were carefully selected to have comparable sites of disease, histology, early-stage disease, and treatment delivered, thus increasing the power of this study by controlling for other independent factors affecting outcome. RESULTS: Sixty percent of patients demonstrated overexpression of p53 in tissue samples. Accumulation of p53 was not predictive of tumor grade, stage, or smoking status prior to diagnosis. p53 status was not predictive of treatment outcome parameters including local-regional failure rate and disease-free survival rate. Factors significantly affecting treatment outcome were stage and dose of radiotherapy in T2 patients (50 Gy vs. > 62 Gy). CONCLUSION: m-p53 protein detected by IHC staining was not predictive as a prognostic factor for clinical outcome following radiation therapy for early-stage glottic SCC. This is in general agreement with other recently published studies of laryngeal carcinoma patients treated with radiation or surgery. At the present time, p53 status should not be used as a marker for prognosis and clinical outcome in laryngeal SCC.

Para-aortic irradiation only appears to be adequate treatment for patients with Stage I seminoma of the testis.

PURPOSE: Results of treatment of patients with Stage I seminoma with orchiectomy and radiotherapy are excellent. Even without adjuvant radiotherapy, the relapse rate is only 15-20%; most of the patients fail in the retroperitoneum, with rare failures observed in the pelvis (0.5-2%). In 1991, we began a prospective study evaluating para-aortic lymph node radiation as the only adjuvant treatment for such patients. This paper reports our preliminary results. MATERIALS & METHODS: Between March 1991 and January 1996, 35 patients with histologically proven Stage I seminoma were entered in the study. Median age was 37.9 years (range: 27-65 years). A radical inguinal orchiectomy was performed in all patients. Staging workup consisted of a chest X-ray; B-HCG, alpha-fetoprotein, and CT scan of the abdomen and pelvis in all patients. Lymphangiogram was done in 23 (66%) of 35 patients for further evaluation of the retroperitoneal lymph nodes. Radiotherapy consisted of treatment to the para-aortic region only. Parallel opposed fields extending from the top of T11 to the bottom of L5 were used. The median field size was 8.7 x 21.8 cm (range: 7-11 x 18-26 cm). The median total dose, prescribed at midpoint, was 25 Gy given in 15 daily fractions of 1.66 Gy. Follow-up was performed every 3 months for the first year, every 4-5 months for the second and third years, and every 6 months thereafter. Chest X-ray, tumor markers, and CT scan of the pelvis were performed routinely as part of the follow-up investigation. RESULTS: At a median follow-up of 39.7 months (range: 16-74 months), 34 (97.1%) of 35 patients are alive with no evidence of disease for an overall actuarial survival rate of 97.1% at 5 years and a cause-specific actuarial survival rate of 100%. Treatment morbidity was limited to Grade I-II acute side effects in 18 (51.4%) of 35 patients. No late side effects were seen. CONCLUSION: From our preliminary results, adjuvant radiation treatment limited to the para-aortic lymph node region, without ipsilateral pelvic irradiation, appears to be adequate treatment for Stage I seminoma. Such an approach in our patients resulted in minimal toxicity and excellent disease-free survival.

Radiosurgery and accelerated radiotherapy for patients with glioblastoma.

OBJECTIVE: To assess the feasibility, toxicity, and local control of stereotactic radiosurgery followed by accelerated external beam radiotherapy (AEBR) for patients with glioblastoma multiforme. MATERIALS AND METHODS: Six males and eight females, with a median age of 67.5 years (range 45-78 years), entered the study. Karnofsky performance status was 90 for five, 80 for six, and 60 for three patients. Following surgery, the patients were left with a residual mass 4 cm. Radiosurgery was delivered with a single dose of 20 Gy to the 90% isodose surface corresponding to the contrast-enhancing edge of the tumour. A total AEBR dose of 60 Gy in 30 fractions was delivered using a concomitant boost technique over four weeks. RESULTS: Median survival time was 40 weeks (range 17-80 weeks). Actuarial survivals at 12 and 18 months were 43% and 14%, respectively. The median time to progression was 25 weeks (range 2-77 weeks). One patient developed a seizure on the day of stereotactic radiosurgery. Two patients experienced somnolence at 47 and 67 days post-radiotherapy. Eight patients remained steroid-dependent. Radiological evidence of leukoencephalopathy was observed in one patient, and brain necrosis in two additional patients at 30 and 63 weeks. One of these two patients with brain necrosis developed complete loss of vision in one eye, and decreased vision in the contralateral eye at 63 weeks. CONCLUSION: Stereotactic radiosurgery followed by AEBR was feasible but was associated with late complications. The use of such radiosurgical boost for patients with glioblastoma multiforme should be reserved for those patients entering controlled clinical trials.

Impact of radiation therapy fraction size on local control of early glottic carcinoma.

PURPOSE: Different radiotherapy fractionation schedules were used over a 10-year period to treat patients with early squamous cell carcinoma of the vocal cords at McGill University. A retrospective analysis was performed to study the effect of fraction size on local control in this group of patients. METHODS AND MATERIALS: A total of 126 previously untreated patients with T1 invasive squamous cell carcinoma of the true vocal cords were irradiated between January 1978 and December 1988 in the Department of Radiation Oncology at McGill University. All patients received megavoltage irradiation, 94 patients received daily fractions > 2 Gy (64 patients received 50 Gy with once-daily 2.5-Gy fractions, and 30 received 65.25 Gy in 29 fractions of 2.25 Gy each), and 32 patients were treated to a dose of 66 Gy in 33 fractions with 2 Gy/fraction. Patients' characteristics of prognostic importance were equally distributed between the two fractionation groups. RESULTS: At a median follow-up of 84 months, the 10-year disease-free survival and overall survival were 76% and 93%, respectively. Local control for patients treated with > 2 Gy fraction was 84%, compared to 65.6% for those treated with 2-Gy fractions (p = 0.026). Among the prognostic factors tested, such as gender, age, stage, anterior and posterior commissure involvement, smoking history, and fraction size, the latter was the only significant predictor of local control for the whole group of patients in univariate (p = 0.041) and multivariate (p = 0.023) analysis. There was no observed difference in the incidence of complications between the two fractionation groups. CONCLUSIONS: From the results of this retrospective review of patients treated with radiotherapy for T1 true vocal cord cancer, and within the range of total doses and overall treatment times used in our patients, it was found that fractionation schedules using daily fraction size > 2 Gy are associated with a better local control than schedules delivering 2 Gy/fraction, with no increase in toxicity.

Tamoxifen metabolic patterns within a glioma patient population treated with high-dose tamoxifen.

AIMS: The study was designed to evaluate tamoxifen metabolic profiles in 25 patients (13 M, 12 F) suffering from recurrent high-grade cerebral astrocytomas who were treated with high oral doses of tamoxifen (120 mg/m2 twice daily). METHODS: Tamoxifen was administered for at least 8 weeks; after 4 weeks blood samples were collected 7 h post dose. Tamoxifen and metabolites were analysed by h.p.l.c. RESULTS: Steady-state plasma concentrations (mean microM +/- s.d.) were determined for tamoxifen (2.94 +/- 3.44), N-desmethyltamoxifen (4.37 +/- 2.13), N-desdimethyltamoxifen (1.49 +/- 0.54), 4-hydroxytamoxifen (0.13 +/- 0.05) and tamoxifen primary alcohol (1.07 +/- 0.46). Male and female patients had comparable metabolic profiles, both qualitatively and quantitatively. The mean plasma tamoxifen concentrations were higher in dexamethasone-treated patients than untreated patients: 3.94 +/- 4.35 microM (95% C.I.: 1.43-6.46) vs 1.67 +/- 0.84 microM (95% C.I.: 1.11-2.24), with vs without; while phenytoin-treated patients had lower concentrations: 1.85 +/- 0.87 microM (95% C.I.: 1.37-2.34) vs 4.58 +/- 5.05 microM (95% C.I.: 0.97-8.19), with vs without. The differences approached but did not reach statistical significance (P = 0.065 and 0.078 respectively). CONCLUSIONS: There was marked interpatient variability. The observed effect of dexamethasone on tamoxifen concentrations is consistent with the involvement of CYP3A in metabolism.

Generation of therapeutic T cells from draining lymph nodes in a murine model of head and neck squamous cell carcinoma.

OBJECTIVES: To study immunotherapy for advanced head and neck squamous cell carcinoma using AT-84, a spontaneously arising murine tumor. We examined the draining lymph nodes (DLNs) for generation of potential therapeutic lymphocytes in head and neck squamous cell carcinoma. DESIGN: Experimental randomized control trial. INTERVENTION: Therapeutic T cells from DLNs were generated by the sequential activation of the in vivo-primed DLN cells with 2C11, and anti-CD3 antibody, and interleukin-2 (IL-2). Immunotherapy of mice bearing lung metastases was carried out in various experiments with low-dose systemic IL-2 and activated DLN cells. Using a 4-hour radioactive chromium Cr 51 release assay, in vitro cytotoxicity of these cells also was examined. RESULTS: Mice immunized with this tumor failed to reject the growth of a subsequent challenge with the tumor. Immunotherapy with low-dose systemic IL-2 resulted in a mean reduction of 79% in the number of lung metastases. Adoptive immunotherapy with activated DLN cells was effective in all experiments, with a mean reduction of 59% in the number of metastases in immunodeficient mice. However, DLN cells were not directly cytotoxic to the tumor cells in in vitro assays, unlike control lymphokine-activated killer cells. CONCLUSIONS: AT-84 is a nonimmunogenic tumor similar to many human malignant neoplasms, making this a suitable model for immunotherapy. Low-dose systemic IL-2 was effective in reduction of established metastasis in this model. Activated DLN cells show reproducible in vivo therapeutic efficacy despite lack of in vitro cytotoxicity. Use of DLN cells as sources of therapeutic T cells in patients with head and neck squamous cell carcinoma deserves exploration because they are readily obtainable and because conventional treatment is of limited benefit.

Familial risks of squamous cell carcinoma of the head and neck: retrospective case-control study.

OBJECTIVE: To determine the contribution of inheritance to the incidence of squamous cell carcinoma of the head and neck. DESIGN: Historical cohort study. First degree relatives of cases with squamous cell carcinoma of the head and neck made up the exposed cohort and first degree relatives of spouses of cases made up the comparison unexposed cohort. SETTING: Ear, nose, and throat clinic in a large metropolitan teaching hospital. SUBJECTS: 1429 first degree relatives of 242 index cases of squamous cell carcinoma of the head and neck; as controls, 934 first degree relatives of the spouses of 156 index cases. MAIN OUTCOME MEASURES: Relative risk of developing squamous cell carcinoma in first degree relatives of cases compared with risk in first degree relatives of spouses. RESULTS: The adjusted relative risk for developing head and neck cancer if the index case had squamous cell carcinoma of the head and neck was 3.79 (95% confidence interval 1.11 to 13.0). There were no significantly increased risks associated with a family history of cancer at other sites. The adjusted relative risk for squamous cell carcinoma of the head and neck was 7.89 (1.50 to 41.6) in first degree relatives of patients with multiple primary head and neck tumours. CONCLUSIONS: These data suggest that genetic factors are important in the aetiology of head and neck cancer, in particular for patients with multiple primary cancers. Given the prolonged exposure of these subjects to carcinogens, these genetic factors may have a role in modifying carcinogen activity or in host resistance to carcinogens. Inherited factors may be important in persons with environmentally induced cancers.

Glottic microinvasive carcinoma: is it different from carcinoma in situ?

OBJECTIVE: To determine the impact of different treatment modalities on the outcome of microinvasive carcinoma. DESIGN: Retrospective review of patients presenting between 1976 and 1990. SETTING: Fifteen patients with microinvasive carcinoma (MIC) of the glottic larynx treated at McGill University teaching hospitals. METHODS: All patients had MIC involving the glottis confirmed pathologically. Nine patients (60%) had right vocal cord involvement, four (27%) had left vocal cord involvement, and two (13%) had involvement of both cords. Five patients (33%) were treated by stripping(S), three patients (20%) by stripping and radiotherapy (S + RT), and six patients (40%) by radiotherapy (RT) alone as the primary treatment. Only one patient underwent hemilaryngectomy. RESULTS: With a median follow-up time of 63 months (range 20-208 months), the 15-year actuarial survival rate is 100% for all patients. CONCLUSIONS: Surgery alone, RT alone, or S + RT is equally effective in treating MIC of the glottic larynx; however, single-modality therapy is preferred. The choice of treatment modality should be individualized for each patient.