[Imaging in the diagnosis of colorectal liver metastases and extrahepatic abnormalities]. / Beeldvormende diagnostiek van colorectale levermetastasen en extrahepatische afwijkingen.

Imaging using ultrasonography, spiral CT, MRI and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), plays a major role at two situations during the management of patients with colorectal liver metastases: (a) at the time of the diagnosis and treatment of the primary colorectal tumour, and (b) during the follow-up for the detection of liver metastases and assessing the resectability of these metastases. At the time of the diagnosis and the treatment of the primary tumour, imaging comprising spiral CT or MRI to detect and characterize liver lesions is considered to be the modality of choice. Due to their low prevalence, imaging for the evaluation of lung metastases may be limited to conventional chest radiography. For evaluation of the extrahepatic abnormalities, abdominal and chest CT may be performed in combination with CT of the liver; alternatively a FDG-PET may be performed. During the follow-up of patients treated for colorectal carcinoma, ultrasonography is the most important imaging modality. However, if the liver cannot be adequately imaged by ultrasonography, if there is a raised level ofcarcinoembryonic antigen or irresectability cannot be determined, additional CT or MRI examination will result in more information.

Preoperative chemoradiation with capecitabine in locally advanced rectal cancer.

BACKGROUND: Preoperative radiation therapy in combination with 5-fluoracil (5-FU) improves local tumour control in locally advanced rectal cancer. The aim of our study was to evaluate the toxicity and efficacy of preoperative chemoradiation using the oral 5-FU prodrug capecitabine in locally advanced rectal cancer. METHODS: Sixty patients with locally advanced rectal cancer were treated with preoperative chemoradiation. Radiotherapy consisted of a total dose of 50 Gy delivered in 25 fractions to the pelvis. Chemotherapy was concurrently administered and consisted of oral capecitabine only on radiotherapy days. Surgery was performed six to ten weeks after completion of chemoradiation. RESULTS: The patient population consisted of 19 females and 41 males, with a median age of 61 years. All but two patients received the full dose of chemoradiation. No grade 3 or 4 haematological toxicities developed. Two patients (3%) developed grade 3 radiation dermatitis and one a grade 3 diarrhoea. All patients underwent definitive surgery; 19 patients underwent an abdominal perineal resection (APR), 25 a low anterior resection (LAR) and 16 patients a Hartmann's procedure. One patient with a low anterior resection developed an anastomotic leakage (4%). Final pathology demonstrated eight patients (13%) with a complete pathological response. Primary tumour and nodal downstaging occurred in 67 and 84% of the patients, respectively. Two patients (3%) had an R1 resection, one after an APR and one after an LAR. CONCLUSION: Preoperative chemoradiation with oral capecitabine is safe and well tolerated in locally advanced rectal cancer patients. This preoperative treatment has a considerable downstaging effect on the tumour and lymph nodes.

A phase I dose escalation study of BIBW 2992, an irreversible dual inhibitor of epidermal growth factor receptor 1 (EGFR) and 2 (HER2) tyrosine kinase in a 2-week on, 2-week off schedule in patients with advanced solid tumours.

To assess tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and clinical activity of the dual epidermal growth factor receptor (EGFR) 1 and 2 (HER2) tyrosine kinase inhibitor BIBW 2992. An escalating schedule of once-daily (OD) BIBW 2992 for 14 days followed by 14 days off medication was explored. Thirty-eight patients were enrolled. Dose levels were 10, 20, 30, 45, 70, 85, and 100 mg. At 100 mg dose-limiting toxicity (DLT) (common toxicity criteria grade 3 skin rash and grade 3 diarrhoea despite treatment with loperamide) occurred in two patients. In the next-lower dose of 70 mg, DLT (grade 3 fatigue and ALAT elevation) occurred in one of six patients. An intermediate dose level of 85 mg was studied. Here DLT occurred in two patients (grade 3 diarrhoea despite treatment and grade 2 diarrhoea lasting more than 7 days despite treatment). An additional 12 patients were treated at 70 mg. BIBW 2992 PK after single and multiple doses revealed moderately fast absorption, and no deviation from dose proportionality. Pharmacodynamics analysis in skin biopsies did not show significant changes in EGFR-associated biomarkers. However, a significant inhibitory effect on the proliferation index of epidermal keratinocytes was observed. No partial or complete responses were observed, stable disease lasting more than four cycles was seen in seven patients. The recommended dose for studies with BIBW 2992 for 14 days followed by 14 days off medication is 70 mg OD.

[Myocardial ischaemia as a result of treatment with capecitabine]. / Myocardischemie als gevolg van behandeling met capecitabine.

A 53-year-old man and a 76-year-old woman were treated with the cytotoxic drug capecitabine as palliative treatment and adjuvant treatment, respectively, because of colorectal carcinoma. Both developed myocardial ischaemia within a few days. In the man, the capecitabine dosage was reduced and metoprolol was prescribed, while in the woman the capecitabine was stopped. According to the literature, the risk of myocardial ischaemia during treatment with capecitabine is approximately 0.4%, irrespective of the patient's medical history. Except in clinical trials, a history of coronary disease is not considered a contraindication for capecitabine treatment. In case stable angina pectoris develops during treatment, continuation of treatment with a reduced dosage of capecitabine can be considered. A switch to treatment with an alternative fluoropyrimidine, such as fluorouracil or raltitrexed, also appears to be safe. However, raltitrexed is no longer available in The Netherlands.

A multicentre phase I and pharmacokinetic study of BN80915 (diflomotecan) administered daily as a 20-min intravenous infusion for 5 days every 3 weeks to patients with advanced solid tumours.

BACKGROUND: BN80915 (diflomotecan) is an E-ring modified camptothecin analogue, which possesses greater lactone stability in plasma compared with other topoisomerase I inhibitors. This phase I study was carried out using a daily times five administration schedule (dx5) repeated three weekly. The primary objective was to determine the maximum tolerated dose (MTD) and recommended dose (RD) for phase II studies. Secondary objectives were to determine the safety and pharmacokinetic (PK) profile, and to make a preliminary assessment of antitumour activity. PATIENTS AND METHODS: Diflomotecan was administered intravenously on days 1-5 every 3 weeks. Patients were treated in cohorts of three to six per dose level and the dose of diflomotecan was escalated according to modified Fibonacci schedule. Plasma concentrations of diflomotecan and its metabolite BN80942 were quantified. RESULTS: Thirty patients were assessable for toxicity. Dose levels explored were 0.05, 0.1, 0.125 and 0.15 mg/m(2)/day. The 0.15-mg/m(2) dose level was determined to be the MTD. Toxicity was acceptable at the 0.125-mg/m(2)/day dose level. PK analysis showed the principal parameters were neither time nor dose dependent. There was a wide interpatient variability in PK at all dose levels. One patient with colorectal cancer, previously treated with irinotecan, had a partial response. A further eight patients had disease stabilisation. CONCLUSIONS: The MTD and RD of diflomotecan administered according to a dx5 repeated three weekly are 0.15 and 0.125 mg/m(2)/day, respectively. In general, treatment was well tolerated; the principal toxicity was reversible myelosuppression. An objective response was seen in a patient previously treated with irinotecan.

Evidence-base guideline on management of colorectal liver metastases in the Netherlands.

A dutch national evidence-based guideline on the diagnosis and treatment of patients with colorectal liver metastases has been developed. The most important recommendations are as follows. For synchronous liver metastases, spiral computed tomography (CT) or magnetic resonance imaging (MRI) should be used as imaging. For evaluation of lung metastases, imaging can be limited to chest radiography. For detection of metachronous liver metastases, ultrasonography could be performed as initial modality if the entire liver is adequately visualised. In doubtful cases or potential candidates for surgery, CT or MRI should be performed as additional imaging. For evaluation of extrahepatic disease, abdominal and chest CT could be performed. Fluorodeoxyglucose positron emission tomography could be valuable in patients selected for surgery based on CT (liver/abdomen/chest), for identifying additional extrahepatic disease. Surgical resection is the treatment of choice with a five-year survival of 30 to 40%. Variation in selection criteria for surgery is caused by inconclusive data in the literature concerning surgical margins.

Phase I study of concomitant chemoradiation with raltitrexed in locally advanced head and neck cancer.

In patients with non-resectable head and neck cancer concomitant chemoradiotherapy is increasingly used, especially in cases of oropharyngeal and hypopharyngeal tumours. Most chemoradiotherapy regimes contain cisplatin as a single agent or in combination with fluorouracil. However, not all patients are fit enough for a cisplatin-containing regime or they refuse hospital admission. Raltitrexed is a specific thymidylate synthase inhibitor that has been studied as a radiosensitiser in rectal cancer. Raltitrexed can be administered easily in an outpatient setting and has few short-term effects. We studied raltitrexed at escalating doses combined with standard radiotherapy in advanced head and neck cancer patients. Seventeen patients with locally advanced head and neck cancers were enrolled in the study. Raltitrexed was administered at dose levels of 1.5, 2.0, 2.5 and 3.0 mg/m(2) intravenously (i.v), once every 3 weeks, for two doses. Radiotherapy consisted of 70 Gy given over 7 weeks in five fractions of 2 Gy per week. In general, treatment toxicity (DLT), complicated febrile neutropenia, was observed at 3.0 mg/m(2) in two of four patients. The dose of 2.5 mg/m(2) was extended thereafter with additional patients without major toxicity. Radiotherapy had to be interrupted in one patient. Five patients had a clinical complete response(CR) and eleven a partial response (PR) six weeks after the last fraction of radiotherapy. Twelve out of 17 patients remained free of locoregional recurrence after a median follow-up of 24(+) months (range 3-60+ months). Raltitrexed, at a dose of 2.5 mg/m(2) given twice 3 weeks apart, can be administered in combination with 70 Gy of radiotherapy in locally advanced head and neck cancer patients with a manageable tolerability profile. The clinical results and convenience of the schedule make raltitrexed an attractive drug to explore further in patients considered unfit for cisplatin-containing chemoradiation regimens.

A phase I and pharmacologic study of the MDR converter GF120918 in combination with doxorubicin in patients with advanced solid tumors.

BACKGROUND: Resistance to chemotherapy can partly be explained by the activity of membrane bound P-glycoprotein. Competitive inhibition of P-glycoprotein, by multidrug resistance (MDR) converters, may overcome this MDR. Previously studied MDR converters either have serious intrinsic side effects or considerably influence the pharmacokinetics of cytotoxic agents at concentrations theoretically required to convert MDR. GF120918 is a third-generation MDR converter with high affinity for P-glycoprotein and can be given orally. We performed a phase 1 study with escalating doses of GF120918 in combination with doxorubicin. PATIENTS AND METHODS: The study group comprised 46 patients with advanced solid tumors. Doxorubicin was administered on day 1 (cycle 1), GF120918 on days 22-24 (cycle 2), and on days 29-33 with doxorubicin administered on day 31 (cycle 3). Pharmacokinetics of both GF120918 and doxorubicin were studied. The starting daily dose of GF120918 was 50 mg and was to be increased in subsequent cohorts until a steady state plasma level of 100 ng/ml was reached. The starting dose of doxorubicin was 50 mg/m2 and was to be increased after reaching the target dose level of GF120918. RESULTS: In 37 of the 46 patients, full pharmacokinetic data from the three scheduled cycles were obtained. Pharmacokinetics of GF120918 showed a less than linear increase in Cmax with increasing doses, with considerable interpatient variation. The target steady-state plasma level for GF120918 was exceeded in 12 out of 19 patients who received 400 mg GF120918 alone twice daily and in 12 of 17 patients who received 400 mg GF120918 twice daily in combination with doxorubicin. GF120918 pharmacokinetics were not influenced by coadministration of doxorubicin. The doxorubicin AUC was only marginally influenced by GF120918 and only at the highest dose levels. In these patients there was a significant increase in the AUC of doxorubicinol in cycle 3 as compared to cycle 1. Hematologic toxicity mainly consisted of neutropenia and was more severe in cycle 3 than in cycle 1 (13 vs 5 patients with grade 4 neutropenia, P=0.003). Neutropenic fever was the dose-limiting toxicity at a doxorubicin dose of 75 mg/m2 with 400 mg GF120918 twice daily. The toxicity of GF120918 was limited to somnolence in eight patients and occasional gastrointestinal complaints. CONCLUSION: GF120918 is an MDR converter with only minimal side effects at a dose level yielding concentrations able to convert the action of P-glycoprotein in vitro. A doxorubicin dose of 60 mg/m2 on day 3 in combination with 400 mg GF120918 twice daily on days 1-5 is an acceptable regimen for further clinical trials.

Phase I and pharmacokinetic study of irinotecan in combination with R115777, a farnesyl protein transferase inhibitor.

The aims of this study were to determine the maximum-tolerated dose (MTD), toxicity profile, and pharmacokinetics of irinotecan given with oral R115777 (tipifarnib), a farnesyl protein transferase inhibitor. Patients were treated with escalating doses of irinotecan with interval-modulated dosing of R115777 (continuously or on days 1-14, and repeated every 21 days). In total, 35 patients were entered onto the trial for a median duration of treatment of 43 days (range, 5-224 days). Neutropenia and thrombocytopenia were the dose-limiting toxicities; other side effects were mostly mild. The MTD was established at R115777 300 mg b.i.d. for 14 consecutive days with irinotecan 350 mg x m(-2) given every 3 weeks starting on day 1. Three patients had a partial response and 14 had stable disease. In the continuous schedule, the area under the curves of irinotecan and its active metabolite SN-38 were 20.0% (P=0.004) and 38.0% (P<0.001) increased by R115777, respectively. Intermittent dosing of R115777 at a dose of 300 mg b.i.d. for 14 days every 3 weeks is the recommended dose of R115777 in combination with the recommended single-agent irinotecan dose of 350 mg x m(-2).

Real-time pharmacokinetics guiding clinical decisions; phase I study of a weekly schedule of liposome encapsulated paclitaxel in patients with solid tumours.

The purpose of this weekly schedule phase I study of liposome encapsulated paclitaxel (LEP) was to define the maximum-tolerated dose (MTD), the recommended dose (RD), the dose-limiting toxicities (DLTs), the pharmacokinetic profiles, and to evaluate preliminarily antitumour effects in patients with refractory solid malignancies. LEP was administered as an intravenous (i.v.) infusion over 45 min once every week for 6 out of 8 weeks. Fourteen patients were treated at doses ranging from 90 to 150 mg/m(2)/week. In one patient, DLT was observed at the dose level of 150 mg/m(2)/week, who received less than 70% of the intended cumulative dose. No cumulative toxicities were observed. Stabilisation of disease for 8 weeks was documented in two patients. The whole blood clearance of total paclitaxel was similar for LEP (15.3+/-8.98 l/h/m(2)) and Taxol (17.5+/-3.43 l/h/m(2)), and the extraliposomal to total drug ratio increased rapidly to unity at later sampling time points. The trial was discontinued upon completion of enrolment of the 150 mg/m(2)/week cohort because an assessment of the pharmacokinetics and clinical data suggested that LEP was unlikely to have any advantages over Taxol. It is concluded that this formulation of LEP is unlikely to provide improvements over the taxanes currently in clinical use.

Weekly high-dose cisplatin is a feasible treatment option: analysis on prognostic factors for toxicity in 400 patients.

In the present study we describe the toxicity of weekly high-dose (70-85 mg x m(-2)) cisplatin in 400 patients (203 men, 197 women; median age 54 years) with advanced solid tumours treated in the period 1990-2001 who took part in phase I/II trials, investigating the feasibility and efficacy of weekly cisplatin alone, or in combination with paclitaxel or etoposide. Cisplatin was administered in 250 ml NaCl 3% over 3 h, for six intended administrations. The mean number of administrations was 5.3 (range, 1-6 administrations). Reasons not to complete six cycles were disease progression (7.5%), haematological toxicity (9%), nephrotoxicity (7%), ototoxicity (2.5%), neurotoxicity (1%), gastrointestinal toxicity (1%), cardiovascular complications (0.5%) or a combination of reasons including noncompliance and patient's request (5.5%). Logistic regression analysis was used to evaluate baseline parameters for prognostic value regarding toxicity. Leukopenia correlated with etoposide cotreatment, and thrombocytopenia with cisplatin dose and prior (platinum-based) chemotherapy. Risk factors for nephrotoxicity were older age, female gender, smoking, hypoalbuminaemia and paclitaxel coadministration. Neurotoxicity >grade 1 (11% of patients) was associated with prior chemotherapy and paclitaxel coadministration. Symptomatic hearing loss occurred in 15% with anaemia as the predisposing factor. We conclude that weekly high-dose cisplatin administered in hypertonic saline is a feasible treatment regimen.

Adaptive intrapatient dose escalation of cisplatin in combination with low-dose vp16 in patients with nonsmall cell lung cancer.

The objective of this phase II and pharmacologic study was to explore the feasibility, toxicity and activity of adaptive intrapatient dose escalation of cisplatin in a dose-intensive weekly schedule using predefined levels of exposure, with the ultimate aim to improve the antitumour activity of the therapy in patients with nonsmall cell lung cancer (NSCLC). Platinum DNA-adduct levels in peripheral white blood cells during treatment were used as the primary parameter for adaptive dosing. If DNA-adduct levels were not available, the area under the concentration-time curve (AUC) of unbound platinum in plasma was used for dose adaptation. Target levels for DNA-adducts and AUC have been defined in a previously performed pharmacologic study. The feasibility of adaptive dosing was tested in 76 patients with stage IIIB and IV NSCLC, who were planned to receive 6 weekly courses of cisplatin at a starting dose of 70 mg m(-2), together with daily low oral dose of 50 mg VP16. In total, 37 patients (49%) who were given more than one course received a dose increase varying from 10 to 55%. The majority of patients reached the defined target levels by a dose increase during course two. Relevant grade 2 neurotoxicity was observed in eight (10%) patients and reversible ototoxicity grade 2 in 14 (18%) patients. The strategy of adaptive intrapatient dose adjustment of cisplatin is practically feasible in a research setting even when results for dose adaptation have to be reported within a short time-period of 1 week. The toxicity appeared to be manageable in this cohort of patients. In some patients, exposure after the standard dose was substantially lower than the defined target level and significant dose escalations of more than 50% had to be applied. The response rate (RR) was relatively high: overall 40% (29 out of 72 patients) partial remission (PR), in patients with stage IIIB the RR was 60% (15 out of 25 patients) and with stage IV 30% (14 out of 47 patients). Randomised studies are needed to determine whether the adaptive dosing strategy results in better efficacy than standard dosing.

Weekly oral paclitaxel as first-line treatment in patients with advanced gastric cancer.

BACKGROUND: Pharmacokinetic study has shown that co-administration of cyclosporin A (CsA), which acts as a P-glycoprotein (P-gp) and CYP-3A blocker, resulted in an 8-fold increase in the systemic exposure of oral paclitaxel. Two doses of oral paclitaxel on 1 day in combination with CsA resulted in higher systemic exposure than single dose administration. PATIENTS AND METHODS: In this phase II study, chemonaïve patients with advanced gastric cancer received oral paclitaxel weekly in two doses of 90 mg/m(2) on the same day; CsA (10 mg/kg) was given 30 min before each dose of oral paclitaxel. RESULTS: In 25 patients, the main toxicities were: nausea CTC grade 2/3, 10 patients (40%); vomiting grade 2/3, 4 patients (20%); diarrhea grade 2/3, 6 patients (24%); neutropenia grade 3/4, 5 patients (20%). In the 24 evaluable patients, eight partial responses were observed, resulting in an overall response rate (ORR) of 33% [95% confidence interval (CI) 18% to 52%]. Eleven patients had stable disease (46%) and 5 patients showed progressive disease (21%). The ORR in the total population was 32% (95% CI 17% to 50%). The median time to progression was 16 weeks (95% CI 9-22). Pharmacokinetic analyses revealed that the mean area under the plasma concentration-time curve (AUC) of orally administered paclitaxel (+/- standard deviation) was 3757.6 +/- 939.4 ng.h/ml in week 1 and 3928.4 +/- 1281 ng.h/ml in week 2. The intrapatient variability in the AUC was 12%. CONCLUSIONS: Oral paclitaxel in combination with CsA is both active and safe in chemonaïve patients with advanced gastric cancer. Toxicities were mainly gastrointestinal.

Phase I and pharmacokinetic studies of PNU-159548, a novel alkycycline, administered intravenously to patients with advanced solid tumours.

PNU-159548 (4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyl-daunorubicin) is the lead compound of a novel class of cytotoxic agents (alkycyclines) with a unique mechanism of action combining DNA intercalation with alkylation of guanines in the DNA major groove. The objectives of two phase I studies were to assess the dose-limiting toxicities (DLTs), to determine the maximum tolerated dose (MTD) and to study the pharmacokinetics (PKs) of PNU-159548 and its active metabolite PNU-169884 when administered intravenously (i.v.) over 10 or 60 min to patients with advanced solid tumours. Patients were treated with escalating doses of PNU-159548, courses repeated every 21 days at doses ranging from 1.0 to 16 mg/m(2). For pharmacokinetic analysis, plasma sampling was performed during the first course and assayed using a validated high-performance liquid chromatographic assay with mass spectrometric detection. 69 patients received a total of 161 courses. The MTD was reached at 14 and 16 mg/m(2) in heavily (HP) and minimally pretreated/non-pretreated (MP) patients, respectively, with thrombocytopenia as the DLT. A hypersensitivity reaction was observed in 8 patients across all dose levels, characterised by fever with chills, erythema, facial oedema and dyspnoea. The PKs of PNU-159548 and PNU-169884 were linear over the dose range studied. A significant correlation was observed between the percentage decrease in platelet count and the AUC of PNU-159548. In these studies, the DLT of PNU-159548 was thrombocytopenia. The recommended dose for phase II studies of PNU-159548 is 12 and 14 mg/m(2) administered i.v. over 10 min, once every 21 days, in HP and MP patients, respectively.

The impact of drug administration sequence and pharmacokinetic interaction in a phase I study of the combination of docetaxel and gemcitabine in patients with advanced solid tumors.

Our objective was to determine the maximum tolerated dose (MTD) of two administration sequences of docetaxel and gemcitabine in cancer patients, and to describe the pharmacokinetics of both drugs. Patients were treated in a 4-weekly schedule at two dose levels: gemcitabine 800 mg/m2 on days 1, 8 and 15, and docetaxel 85 or 100 mg/m2 on day 15 (levels I and II). The protocol was amended to a 3-weekly schedule, testing gemcitabine 800 or 1000 mg/m2 on days 1 and 8, with docetaxel 85 mg/m2 on day 8 given initially (dose levels IIIa and IV). At the recommended dose, an extra cohort of patients initially received gemcitabine (dose level IIIb). Eleven patients were treated with the 4-week schedule; 29% of cycles were delayed predominantly because of hematological toxicity. Four patients developed dose-limiting toxicities (DLTs), predominantly hematological. In the 3-week schedule, 14 patients were treated. At level IV, three of four patients developed DLTs, defining the MTD. With the reverse sequence, three patients received a total of 10 cycles. Overall, nine partial remissions were observed. We conclude the recommended dose for phase II studies is gemcitabine 800 mg/m2 on days 1 and 8, combined with docetaxel 85 mg/m2 on day 8, on a 3-weekly schedule. Gemcitabine distribution is significantly altered upon docetaxel administration.

Results of a randomised phase II study of cisplatin plus 5-fluorouracil versus cisplatin plus 5-fluorouracil with alpha-interferon in metastatic pancreatic cancer: an EORTC gastrointestinal tract cancer group trial.

A randomised phase II study of 5-fluorouracil (5-FU) plus cisplatin (CDDP) with or without alpha-interferon 2b was performed in patients with pancreatic cancer with measurable metastatic disease outside the pancreas. The treatment in arm A consisted of cisplatin (100 mg/m(2)) on day 1, followed by a continuous infusion of 5-FU 1000 mg/m(2) for 4 days and in arm B the same treatment was given plus alpha-interferon 2b in a dose of 3 million Units/day subcutaneously (s.c.) from day 1 for 5 days. 36 patients were entered in the trial, 18 in each arm. In arm B only 15 patients were eligible. No responses were observed in the 5-FU/CDDP arm and only 2 partial responses were achieved in the interferon-arm, lasting 27 and 32 weeks, respectively. Both treatment arms showed considerable toxicity. It has to be concluded that both treatment regimens have little activity and cannot be recommended.

Adaptive intrapatient dose escalation of cisplatin in patients with advanced head and neck cancer.

The purpose of this study was to explore the feasibility and toxicity of intrapatient dose adjustment using predefined levels of exposure to cisplatin, with the ultimate goal to further improve the antitumor activity of the treatment. The primary parameter for adaptive dosing was the level of platinum DNA adducts in peripheral white blood cells (WBC) and the secondary parameter the area under the curve (AUC) of unbound platinum in plasma, which were determined during the applied courses. Target levels had been defined in a previously performed pharmacologic study. The concept of adaptive dosing was tested in 16 patients with locally advanced head and neck (H/N) cancer who would receive six weekly courses of cisplatin at a starting dose level of 80 mg/m(2), which was previously investigated in a phase II study. Forty-seven percent of patients received a dose increase varying from 10 to 40%. Only two patients had exposure levels significantly below the defined target levels for DNA adducts and AUC. The majority of patients reached the defined target levels by modest dose increases of 10-20% during course 2. Relevant but reversible ototoxicity (temporary grade 3 in two patients) and renal toxicity (temporary grade 2 in two other patients) were observed. The pattern and severity of the toxicity was comparable to that encountered in the previous phase II study in H/N cancer patients. We conclude that the strategy of intrapatient dose adjustment for cisplatin is practically feasible in a research setting even when a short turn around time of 1 week is the limit for reporting results. Although in some patients the dose increase that had to be applied to reach target levels was substantial (up to 40%), this approach in H/N cancer patients is not expected to improve the response rate significantly, because these significantly underdosed patients represented only a small percentage of the investigated population. The great majority of patients needed only limited (10-20%) dose increases which very likely will not improve the response rate to a clinically significant extent. The outlined concept is currently being explored in other tumor types and schedules of cisplatin.

Body-surface area-based dosing does not increase accuracy of predicting cisplatin exposure.

PURPOSE: Most anticancer drugs are dosed based on body-surface area (BSA) to reduce interindividual variability of drug effects. We evaluated the relevance of this concept for cisplatin by analyzing cisplatin pharmacokinetics obtained in prospective studies in a large patient population. PATIENTS AND METHODS: Data were obtained from 268 adult patients (163 males/105 females; median age, 54 years [range, 21 to 74 years]) with advanced solid tumors treated in phase I/II trials with cisplatin monotherapy or combination chemotherapy with etoposide, irinotecan, topotecan, or docetaxel. Cisplatin was administered either weekly (n = 93) or once every 3 weeks (n = 175) at dose levels of 50 to 100 mg/m(2) (3-hour infusion). Analysis of 485 complete courses was based on measurement of total and non-protein-bound cisplatin in plasma by atomic absorption spectrometry. RESULTS: No pharmacokinetic interaction was found between cisplatin and the anticancer drugs used in combination therapies. A linear correlation was observed between area under the curves of unbound and total cisplatin (r = 0.63). The mean plasma clearance of unbound cisplatin (CL(free)) was 57.1 +/- 14.7 L/h (range, 31.0 to 116 L/h), with an interpatient variability of 25.6%. BSA varied between 1.43 and 2.40 m(2) (mean, 1.86 +/- 0.19 m(2)), with an interpatient variability of 10.4%. When CL(free) was corrected for BSA, interindividual variability remained in the same order (23.6 v 25.6%). Only a weak correlation was found between CL(free) and BSA (r = 0.42). Intrapatient variability in CL(free), calculated from 90 patients was 12.1% +/- 7.8% (range, 0.30% to 32.7%). CONCLUSION: In view of the high interpatient variability in CL(free) relative to variation in observed BSA, no rationale for continuing BSA-based dosing was found. We recommend fixed-dosing regimens for cisplatin.