Biomedical subjects
Alan Horwich
Publications and source records attributed to Alan Horwich.
Testicular germ-cell cancer.
Testicular germ-cell tumours (TGCTs) represent the model of a curable malignancy; sensitive tumour markers, accurate prognostic classification, logical series of management trials, and high cure rates in both seminomas and non-seminomas have enabled a framework of effective cancer therapy. Understanding the molecular biology of TGCT could help improve treatment of other cancers. The typical presentation in young adults means that issues of long-term toxicity become especially important in judging appropriate management. A focus of recent developments has been to tailor aggressiveness of treatment to the severity of the prognosis. Recent changes affect the most common subtypes and include the reduction of chemotherapy for patients who have metastastic non-seminomas and a good prognosis, and alternatives to adjuvant radiotherapy in stage I seminomas. We summarise advances in the understanding and management of TGCT during the past decade.
Retroperitoneal lymph-node dissection after chemotherapy for germ cell cancer in patients with elevated tumor markers.
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Recovery of serum testosterone after neoadjuvant androgen deprivation therapy and radical radiotherapy in localized prostate cancer.
OBJECTIVE: To prospectively evaluate the time-course of recovery of serum testosterone levels after a short course of luteinizing hormone-releasing hormone analogue (LHRHa) and radical radiotherapy to the prostate. PATIENTS AND METHODS: Testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were sequentially measured prospectively in 59 men who received short-course LHRHa treatment and radiotherapy for localized prostate cancer. Measurements were made before treatment (baseline), during LHRHa treatment, and at 6, 12, 18, 24 and >40 weeks after the last LHRHa injection. RESULTS: The median (range) time from the first to last LHRHa injection was 116 (54-194) days. The mean (95% confidence interval) testosterone levels (in nmol/L) at baseline, during treatment and at 6, 12, 18, 24 and >40 weeks afterward were 12.0 (10.8-13.1), 0.6 (0.5-0.7), 1.4 (0.6-2.2), 11.4 (9.7-13), 12.2 (10.5-14), 10.4 (8.9-12) and 11.7 (10.5-13). Four men had low baseline testosterone levels (<6.1 nmol/L). At 6 weeks after the last LHRHa injection, no men had testosterone levels in the 'normal' range; 35% were in the normal range at 12 weeks, 85% at 18 weeks, 89% at 24 weeks, and 96% at 1 year. CONCLUSION: After LHRHa treatment and radiotherapy, the testosterone levels of most men had recovered to normal by 18-24 weeks after the last LHRHa injection.
Treating stage I nonseminomatous germ cell tumours with a single cycle of chemotherapy.
OBJECTIVE: To estimate the rate of relapse in men with stage I nonseminomatous germ cell tumours (NSGCT) of the testis treated with one cycle of chemotherapy instead of the usual two cycles. PATIENTS AND METHODS: Between 1992 and 1996, 22 men with stage I NSGCT who had normalized tumour markers after orchidectomy and negative findings on computed tomography, and who were at moderate risk of relapse, were treated with one cycle of platinum-containing chemotherapy (bleomycin and etoposide with either cisplatin or carboplatin). RESULTS: At a median follow-up of 10.2 years, none of the patients have relapsed with malignant GCTs. CONCLUSION: The results after one cycle of chemotherapy are no worse than after two cycles. The present study needs to be replicated in a larger cohort of patients to define the relapse risk more accurately. This approach is soon to be tested in a large multicentre trial randomizing patients between one and two cycles.
Site of relapse after chemotherapy alone for stage I and II Hodgkin's disease.
BACKGROUND: Short course chemotherapy followed by radiotherapy is a standard treatment for early Hodgkin's disease. There is yet no consensus regarding the appropriate radiotherapy portal following chemotherapy. A good guide to the adjuvant radiotherapy field is the site of relapse in patients treated with chemotherapy alone. PATIENTS AND METHODS: From 1980 to 1996, 61 patients with stage I and II supradiaphragmatic Hodgkin's disease were treated with chemotherapy alone at the Royal Marsden Hospital. We undertook a retrospective review and failure analysis to define the pattern of recurrence. RESULTS: After a median follow-up of 6.5 years, 24 patients had relapsed giving a 5-year relapse rate of 40%. The 5 and 10-year actuarial survival rates were 94 and 89%, respectively with cause-specific survival being 94% at 5 and 10 years. Two-thirds of the relapses were nodal and supradiaphragmatic. Twenty patients (83%) relapsed in the initially involved sites of disease and this was the sole site of recurrence in 11 (45%) of patients. In retrospect, it appeared that at least 12 recurrences could have been prevented by involved field radiotherapy. Review of detailed imaging data (available in 9 out of 11 patients with recurrences in initial sites of disease) showed that the relapses were always in the initially involved nodes. CONCLUSION: After chemotherapy alone in early stage HD most initial recurrences are nodal. Loco-regional recurrences are in the originally involved nodes. Based on limited data it appears that involved nodal RT is equivalent to involved field radiotherapy and may halve the risk of recurrence.
Guidelines on testicular cancer.
OBJECTIVE: To up-date the 2001 version of the EAU testicular cancer guidelines. METHODS: A non-structured literature review until January 2005 using the MEDLINE database has been performed. Literature has been classified according to evidence-based medicine levels. RESULTS: Testicular cancer is a highly curable disease. Excellent cure rates have been achieved by standardization of treatment, interdisciplinary management, and tremendous success in performing clinical trials. Currently, the aims of testicular cancer treatment are as follows: for patients with low-stage disease, a reduction in treatment is proposed to improve long-term toxicity in these patients with unaltered life expectancy; for about 10% of patients with advanced disease and poor prognosis, intensification of treatment (including high-dose chemotherapy and new drugs as well as aggressive surgical approaches) is being investigated to improve long-term cure rates. CONCLUSION: Guidelines will improve clinical practice only if they are regularly updated. This update presents the state-of-the-art management of testicular cancer patients in 2005.
Randomized trial of 30 versus 20 Gy in the adjuvant treatment of stage I Testicular Seminoma: a report on Medical Research Council Trial TE18, European Organisation for the Research and Treatment of Cancer Trial 30942 (ISRCTN18525328).
PURPOSE: To assess the possibility of reducing radiotherapy doses without compromising efficacy in the management of patients with stage I seminoma. PATIENTS AND METHODS: Patients were randomly assigned 20 Gy/10 fractions over 2 weeks or 30 Gy/15 fractions during 3 weeks after orchidectomy. They completed a symptom diary card during treatment and quality-of-life forms pre- and post-treatment. The trial was powered to exclude absolute differences in 2-year relapse rates of 3% to 4% (alpha = .05 [one sided]; 90% power). RESULTS: From 1995 to 1998, 625 patients were randomly assigned to treatment. Four weeks after starting radiotherapy, significantly more patients receiving 30 Gy reported moderate or severe lethargy (20% v 5%) and an inability to carry out their normal work (46% v 28%). However, by 12 weeks, levels in both groups were similar. With a median follow-up of 61 months, 10 and 11 relapses, respectively, have been reported in the 30- and 20-Gy groups (hazard ratio, 1.11; 90% CI, 0.54 to 2.28). The absolute difference in 2-year relapse rates is 0.7%; the lower 90% confidence limit is 2.9%. Only one patient has died from seminoma (allocated to the 20-Gy treatment group). CONCLUSION: Treatment with 20 Gy in 10 fractions is unlikely to produce relapse rates more than 3% higher than for standard 30 Gy radiation therapy, and data on an additional 469 patients randomly assigned in a subsequent trial support and strengthen these results. Reductions in morbidity enable patients to return to work more rapidly. Prolonged follow-up is required before any inference can be made about any impact of allocated treatment on new primary cancer diagnoses.
Technological advances in radiotherapy for the treatment of localised prostate cancer.
There is good evidence that radiation dose escalation in localised prostate cancer is associated with increased cell kill. The traditional two-dimensional (2D) technique of treatment planning and delivery is limited by normal tissue toxicity, such that the dose that can be safely delivered to the prostate by external beam radiotherapy is 65-70 Gy. Several technological advances over the last 20 years have enhanced the precision of external beam radiotherapy (EBRT), and have resulted in improved outcomes. The three-dimensional conformal radiotherapy (3D-CRT) approach reduces the dose-limiting late side-effect of proctitis and has allowed for dose escalation to the whole prostate to 78 Gy. More recently, intensity modulated radiotherapy (IMRT), an advanced form of conformal therapy, has resulted in reduced rectal toxicity when using doses greater than 80 Gy. In addition, IMRT can potentially escalate the dose to specific parts of the prostate where there are resistant subpopulations of tumour clonogens, or can be used to extend the high-dose region to pelvic lymph nodes. The addition of androgen deprivation to conventional radiotherapy has an impact on survival and local control. Initial hormone therapy causes cytoreduction of the prostate cancer allowing for a reduction in radiotherapy volume as well as an additive effect on cell kill. Long-term adjuvant androgen deprivation has been shown to improve overall survival in more advanced tumours. Prostate brachytherapy is now a recognised treatment for those with low-risk disease. It achieves similar long-term outcome to other treatment modalities. Brachytherapy can be used as monotherapy for localised disease, or as boost treatment following conventional EBRT for locally advanced disease. New techniques are available to improve the precision of both target definition and treatment verification. This so-called image-guided radiotherapy will help to enhance the accuracy of dose delivery by correcting both for inter-fraction positional variation and for intra-fraction movement of the prostate in real-time and will allow for tighter tumour margins and avoidance of normal tissues, thereby enhancing the safety of treatment.
Early outcomes of active surveillance for localized prostate cancer.
OBJECTIVE: To describe the preliminary clinical outcomes of active surveillance (AS), a new strategy aiming to individualize the management of early prostate cancer by selecting only those men with significant cancers for curative therapy, and illustrate the contrast with a policy of watchful waiting (WW). PATIENTS AND METHODS: Eighty men with early prostate cancer began AS at the authors' institution between 1993 and 2002. Eligibility included histologically confirmed prostatic adenocarcinoma, fitness for radical treatment, clinical stage T1/T2, N0/X, M0/X, a prostate specific antigen (PSA) level of < or = 20 ng/mL, and a Gleason score of < or = 7. PSA was measured and a digital rectal examination conducted at 3-6 month intervals. The decision between continued monitoring or radical treatment was informed by the rate of rise of PSA, and was made according to the judgement of each patient and clinician. During the same period, 32 men with localized prostate cancer (any T stage, N0/X, M0/X, any PSA, Gleason score < or = 7) were managed by WW; hormonal treatment was indicated for symptomatic prostate cancer progression. The PSA doubling time (DT) was calculated using linear regression of ln(PSA) against time, using all pretreatment PSA values. RESULTS: At a median follow-up of 42 months, 64 (80%) of the 80 patients on AS remained under observation, 11 (14%) received radical treatment and five (6%) died from other causes. No patient developed evidence of metastatic disease, none started palliative hormone therapy, and there were no deaths from prostate cancer. Of the 11 patients who received radical treatment all remained biochemically controlled with no clinical evidence of recurrent disease. The median PSA DT while on AS was 12 years. Twenty (62%) of the 32 patients on WW remained on observation, eight (25%) received palliative hormonal therapy and four (12%) died, including one from prostate cancer. CONCLUSIONS: AS is feasible in selected men with early prostate cancer. The natural history of this disease often appears extremely indolent, and most men on AS will avoid radical treatment. There is a marked contrast between AS (with radical treatment for biochemical progression) and WW (with palliative treatment for symptomatic progression). Ongoing studies are seeking to optimize the AS protocol, and to compare the long-term outcomes with those of immediate radical treatment.
A randomised trial of accelerated radiotherapy for localised invasive bladder cancer.
BACKGROUND AND PURPOSE: To evaluate the efficacy and toxicity of an accelerated fractionation regimen to treat localised muscle invasive bladder cancer. PATIENTS AND METHODS: A prospective randomised trial was undertaken in 229 patients randomised between 1988 and 1998 comparing accelerated fractionation (AF) to a dose of 60.8 Gy in 32 fractions over 26 days with conventional fractionation (CF) treating to 64 Gy in 32 fractions over 45 days. Accelerated fractionation was delivered using two fractions per day with a 6h gap between fractions and with the first daily fraction size being 1.8 Gy and the second daily fraction size being 2.0 Gy. There was a 1 week treatment gap after the first 12 fractions. Conventional fractionation was one fraction per day, 5 days per week. Eligible patients had clinical stage T2 or T3, N0 or N1, M0 transitional cell carcinoma. The primary endpoint of the trial was local control and the trial was powered to detect a 20% difference (alpha 0.05, power 90%). Secondary endpoints were toxicity and survival. RESULTS: In the initial phase of the trial, randomisation was unequal such that in total 129 patients were randomised to accelerated fractionation and 100 to conventional fractionation. Acute toxicity was evaluable in 121 patients treated with AF and 96 patients treated with CF. RTOG grade 2 or 3 bowel toxicity was noted in 44% of AF patients compared to 26% of CF patients (P trend =0.001). Acute grade 2 or 3 bladder toxicity was seen in 35% of AF patients compared to 36% of CF patients (P=0.99). Late radiation toxicity was evaluated in patients surviving free from local recurrence at 2 years post treatment. Late radiation toxicity equivalent to RTOG grade 2 or more had occurred in 44% (95% CI 34-55%) of AF patients and in 38% (95% CI 26-49%) of CF patients (logrank over 5 years follow-up P=0.23). There was no significant difference in analysis of time to loss of local tumour control comparing the two treatment arms; local recurrence was recorded in 29 of the 100 patients treated with CF and in 41 of 129 patients treated with AF (logrank P=0.86). There was also no significant difference between the treatment arms comparing disease-free survival and overall survival. The overall survival figures at 3 years were for AF 54% (95% CI 45-63%) and for CF 47% (95% CI 36-57%). By 5 years the overall survival was 37% for AF and 40% for CF. There were two treatment related deaths, both on the AF arm of the trial. CONCLUSIONS: This accelerated fractionation schedule did not improve on the efficacy of conventional fractionation for patients with T2 and T3 bladder cancer and accelerated fractionation was associated with increased acute bowel reactions.
Radiotherapy in stage I seminoma of the testis.
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The role of hemoglobin concentration in clinically localized prostate cancer treated with radical radiotherapy +/- neoadjuvant androgen deprivation.
PURPOSE: Serum hemoglobin level (Hb) is a significant determinant of treatment outcome after radical radiotherapy (RT) for several cancer types, but its importance in prostate cancer is not well established. METHODS AND MATERIALS: Two treatment-specific cohorts of men with localized prostate cancer (T1-4, Nx/N0, M0) were analyzed. Seven hundred six men who received radical RT at Princess Margaret Hospital between 1987 and 2000 comprise the RT-alone cohort, of whom 536 had a pre-RT Hb. Six hundred fifty-eight men received 3-6 months' neoadjuvant androgen deprivation (NAD) and radical RT at Royal Marsden Hospital between 1989 and 2000 and comprise the NAD + RT cohort, of whom 475 had a pre-NAD Hb and 513 a pre-RT Hb. Time to biochemical failure (TTBF) was the primary end point. Univariate and multivariate analyses using the Cox proportional hazards regression model were used for each data set independently to study the prognostic role of pre-RT Hb, pre-NAD Hb, nadir Hb (lowest Hb during RT), Hb decrement (pre-NAD Hb - pre-RT Hb), Gleason score, presenting PSA, and T stage. RESULTS: On univariate analysis, no significant association was seen between TTBF and any of the Hb variables for either data set. On multivariate analysis, TTBF was associated with presenting PSA (p < 0.001), Gleason score (p < 0.01), and (for the NAD + RT data set) T stage (p < 0.001), but not pre-NAD Hb (p = 0.24) or pre-RT Hb (p > 0.3). CONCLUSION: Hemoglobin level is not an important determinant of RT outcome in localized prostate cancer.
Intensity modulated radiation therapy.
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Extragonadal germ cell tumors: relation to testicular neoplasia and management options.
An unselected population of 635 consecutive extragonadal GCT patients (EGCT) treated between 1975 through 1996 at 11 cancer centers was retrospectively evaluated for clinical prognosis and biological features of this disease. Five hundred twenty-four patients (83%) had a nonseminomatous GCT, and 104 patients (16%) a seminomatous histology; 341 (54%) patients had a primary mediastinal EGCT, and 283 patients (45%) a retroperitoneal EGCT. Following platinum based induction chemotherapy+/-secondary surgery, 141 patients (49%) with mediastinal nonseminomas (median follow up period: 19 months) and 144 patients (63%) with retroperitoneal nonseminoma (median follow up period: 29 months) are alive [p=0.0006]. In contrast, the overall survival rate for patients with seminomatous EGCT is 88% with no difference between patients with mediastinal or retroperitoneal tumor location (median follow up period: 49 months). Multivariate analysis revealed nonseminomatous histology, the presence of non-pulmonary visceral metastases, primary mediastinal GCT location, and elevated beta-HCG as independent prognostic factors for shorter survival. Sixteen patients (4.1%) developed a metachronous testicular cancer despite the use of platinum based chemotherapy. The cumulative risk of developing a MTC 10-years after a diagnosis of EGCT was 10.3% (95% CI=4.9 to 15.6%), but higher among patients with nonseminomatous EGCT (14.3%; 95% CI=6.7 to 21.9%) or retroperitoneal EGCT location (14.2%; 95% CI=5.6 to 22.8%) than among patients with seminomatous EGCT (1.4%; 95% CI=0.0 to 4.2) or mediastinal EGCT location (6.2%; 95% CI=0.1 to 12.2). After a median follow-up of 51 months (range=1 to 154 months), all 16 MTC patients were alive without disease. Patients with pure seminomatous EGCT histology have a long term chance of cure of almost 90% irrespective of the primary tumor site. Patients with mediastinal nonseminomas have a five-years survival rate of 45%. This outcome is clearly inferior compared to patients with nonseminomatous retroperitoneal primaries who have a five-year survival rate of 62%.
Prognostic factors for relapse in stage I seminoma managed by surveillance: a pooled analysis.
PURPOSE: Several management options are available to patients with stage I seminoma, including adjuvant radiotherapy, surveillance, and adjuvant chemotherapy. We performed a pooled analysis of patients from the four largest surveillance studies to better delineate prognostic factors associated with disease progression. PATIENTS AND METHODS: Individual patient data were obtained from each center (Princess Margaret Hospital, Danish Testicular Cancer Study Group, Royal Marsden Hospital, and Royal London Hospital) for 638 patients. Tumor characteristics (size, histologic subtype, invasion of rete testis, and tumor invasion into small vessels [SVI]) as well as age at diagnosis were analyzed for prognostic importance for relapse. RESULTS: With a median follow-up of 7.0 years (range, 0.02 to 17.5 years), 121 relapses were observed for an actuarial 5-year relapse-free rate (RFR) of 82.3%. On univariate analysis, tumor size (RFR: 4 cm, 76%; P =.003), rete testis invasion (RFR: 86% [absent] v 77% [present], P =.003), and the presence of SVI (RFR: 86% [absent] v 77% [present], P =.038) were predictive of relapse. On multivariate analysis, tumor size ( 4 cm, hazard ratio 2.0; 95% confidence interval [CI], 1.3 to 3.2) and invasion of the rete testis (hazard ratio 1.7; 95% CI, 1.1 to 2.6) remained as important predictors for relapse. CONCLUSION: We have identified size of primary tumor and rete testis invasion as important prognostic factors for relapse in patients with stage I seminoma managed with surveillance. This information will allow patients and clinicians to choose management based on a more accurate assessment of an individual patient's risk of relapse. In addition, it will allow clinicians to tailor follow-up protocols based on risk of occult disease.
Late recurrence in 1263 men with testicular germ cell tumors. Multivariate analysis of risk factors and implications for management.
BACKGROUND: Testicular germ cell tumors are highly curable. However, 10-30% of patients have recurrence after initial treatment. The time-course of recurrence has implications for the duration of follow-up. This study was undertaken to assess the risk and time-course of recurrence and to identify patients at higher risk of late recurrence. METHODS: The records of 1263 patients with primary testicular germ cell tumors presenting to the Royal Marsden Hospital between December 1979 and December 1993 were reviewed. In all, 255 episodes of recurrence were documented (including 44 patients with multiple recurrences) and used to calculate recurrence-free survivals. RESULTS: Fifty-three patients (15 seminomas; 38 nonseminomatous germ cell tumors [NSGCT]) had recurrence more than 2 years after initial presentation. A multivariate analysis of risk of recurrence after 2 years identified positive markers at presentation and the presence of differentiated teratomas in postchemotherapy surgical specimens as significant predictors. Very late recurrence (> 5 years) occurred mainly in patients with metastatic NSGCT (12 of 14 patients) with a 1% annual risk of recurrence between 5 and 10 years. Very late recurrence was also seen in one case of metastatic seminoma and one case of Stage I NSGCT managed by surveillance. Most late recurrences (n = 9) were detected at routine annual follow-up visits but five had recurrences with symptoms leading to an unscheduled clinic visit. CONCLUSION: Late recurrences are rare in patients with testicular germ cell tumors and follow-up to detect recurrence may not be needed after 5 years, except in those presenting with metastatic NSGCTs.
Extragonadal germ cell tumors of the mediastinum and retroperitoneum: results from an international analysis.
PURPOSE: To characterize the clinical and biologic features of extragonadal germ cell tumor (EGCT) and to determine the overall outcome with currently available treatment strategies. PATIENTS AND METHODS: Of an unselected population of 635 consecutive patients treated from 1975 through 1996 at 11 cancer centers, 341 patients (54%) had primary mediastinal EGCT, and 283 patients (45%) had retroperitoneal EGCT. Five hundred twenty-four patients (83%) had a nonseminomatous germ cell tumor (GCT), and 104 patients (16%) had a seminomatous histology. RESULTS: After platinum-based induction chemotherapy with or without secondary surgery, 141 patients (49%) with mediastinal nonseminomas (median follow-up, 19 months; range, 1 to 178 months) and 144 patients (63%) with retroperitoneal nonseminoma (median follow-up, 29 months; range, 1 to 203 months) are alive (P =.0006). In contrast, the overall survival rate for patients with a seminomatous EGCT is 88%, with no difference between patients with mediastinal or retroperitoneal tumor location (median follow-up, 49 months; range, 4 to 193 months; respective 70 months; range, 1 to 211 months). A significantly lower progression-free survival rate was found in seminoma patients treated with initial radiotherapy alone compared with chemotherapy. Nonseminomatous histology, presence of nonpulmonary visceral metastases, primary mediastinal GCT location, and elevated beta-human chorionic gonadotropin were independent prognostic factors for shorter survival. Hematologic malignancies (n = 17) occurred without exception in patients with primary mediastinal nonseminoma. Sixteen patients developed a metachronous testicular cancer despite the use of platinum-based chemotherapy. CONCLUSION: Whereas patients with pure seminomatous EGCT histology have a long-term chance of cure of almost 90% irrespective of the primary tumor site, 45% of patients with mediastinal nonseminomas are alive at 5 years. This outcome is clearly inferior compared with patients with nonseminomatous retroperitoneal primary tumors.