Evaluation of high-dose cisplatin and 5-FU infusion as initial therapy in advanced head and neck cancer

Neoadjuvant Chemotherapy with Continuous Infusion of Cisplatin and Fluorouracil in Stage II-IV, M0 Squamous Cell Carcinoma of the Head and Neck

Aims and Background

The aim of the study was to assess the activity and the toxicity of cisplatin (DDP) and fluorouracil (FU) administered by continuous infusion as neoadjuvant chemotherapy for patients with stage II-IV, MO squamous cell carcinoma of the head and neck.

Methods

Thirty previously untreated patients were submitted to chemotherapy with DDP (20 mg/m2) and FU (1000 mg/m2), both in continuous infusion for 5 days, repeated every 21 days, for a maximum of 5 cycles. Following completion of chemotherapy, the patients underwent radiotherapy; in some patients surgery was performed immediately after chemotherapy. All patients were monitored for response, time to failure, survival, treatment-related events and toxicity.

Results

All patients were evaluated for response; after chemotherapy the complete response rate was 27% and the partial response rate 33%. Twenty-four patients underwent radiotherapy: the overall response rate was 83% (complete response 79%). After a median follow-up of 34 months, the median survival time was 22 months with a median time to failure of 15 months. Acute vascular accidents were the main and unexpected adverse events, with 2 deaths for pulmonary embolism and 1 for stroke. The response rate to the regimen does not seem to be better than that obtained with the standard combination of cisplatin bolus and fluorouracil continuous infusion. The disadvantage of the regimen is that it causes more discomfort for the patient in that it requires hospitalization.

Conclusions

For this reason, we believe that there are no elements for recommending the schedule as neoadjuvant treatment of patients with squamous cell carcinoma of the head and neck or as an experimental arm in a randomized trial.

Targeted endostatin-cytosine deaminase fusion gene therapy plus 5-fluorocytosine suppresses ovarian tumor growth

There are currently no effective therapies for cancer patients with advanced ovarian cancer, therefore developing an efficient and safe strategy is urgent. To ensure cancer-specific targeting, efficient delivery, and efficacy, we developed an ovarian cancer-specific construct (Survivin-VISA-hEndoyCD) composed of the cancer specific promoter survivin in a transgene amplification vector (VISA; VP16-GAL4-WPRE integrated systemic amplifier) to express a secreted human endostatin-yeast cytosine deaminase fusion protein (hEndoyCD) for advanced ovarian cancer treatment. hEndoyCD contains an endostatin domain that has tumor-targeting ability for anti-angiogenesis and a cytosine deaminase domain that converts the prodrug 5-fluorocytosine (5-FC) into the chemotherapeutic drug, 5-fluorouracil. Survivin-VISA-hEndoyCD was found to be highly specific, selectively express secreted hEndoyCD from ovarian cancer cells, and induce cancer-cell killing in vitro and in vivo in the presence of 5-FC without affecting normal cells. In addition, Survivin-VISA-hEndoyCD plus 5-FC showed strong synergistic effects in combination with cisplatin in ovarian cancer cell lines. Intraperitoneal (i.p.) treatment with Survivin-VISA-hEndoyCD coupled with liposome attenuated tumor growth and prolonged survival in mice bearing advanced ovarian tumors. Importantly, there was virtually no severe toxicity when hEndoyCD is expressed by Survivin-VISA plus 5-FC compared with CMV plus 5-FC. Thus, the current study demonstrates an effective cancer-targeted gene therapy that is worthy of development in clinical trials for treating advanced ovarian cancer.

How many cisplatin administration protocols does your department use?

The introduction, 30 years ago, of the co-administration of appropriate hydration and ensuring a diuresis occurs during the administration of cisplatin was important in its development, allowing clinically significant doses to be given with acceptable rates of toxicity. The clinical usage of cisplatin has increased and hydration protocols have been amended to increase patient comfort and reduce resource utilization. We suspected that this had led to unnecessary variations in practice both in clinical trials and subsequently in the clinic. Therefore, we reviewed practice in the Edinburgh Cancer Centre and discovered that 25 different hydration protocols were in use, with wide variation in dilution of cisplatin, total fluid administered, use of electrolyte (potassium and magnesium) supplementation and diuretics. These differences are a reflection of adoption of variations in hydration regimes published in pivotal clinical trials. A review of the available evidence relating to cisplatin associated hydration regimens was performed and recommendations will be made for the future design of evidence-based protocols.

Intra-arterial chemotherapy and its significance in the treatment of oropharyngeal carcinoma

BACKGROUND

In complex therapeutic algorithms for cancer, regional intra-arterial chemotherapy is usually used as an adjuvant and placed in the beginning of treatment. Clinical experience however shows that the achieved remission of malignant tumour illness after non-adjuvant chemotherapy is only temporary and short-lived. The illness progresses relatively quickly if the patient receives no further treatment and most clinical studies have not found any significant increase in life expectancy in oncological patients treated with this method. The question remains to what extent the poor results are due to the treatment method and its position in the therapeutic algorithm, and to what extent they are due to imperfect knowledge of molecular tumour genetics or inappropriate choice of the neoadjuvant intra-arterial chemotherapy

METHODS

We compared preliminary results of immunohistochemical examinations (detection and analysis of expression of proteins Ku 70, STAT 1,3,5 which take part in the regulation of cell cycle apoptosis and repair of damaged DNA, carried out before and after chemotherapy, suggest that depending on the effects of neoadjuvant intra-arterial chemotherapy and patient's survivance.

RESULTS AND CONCLUSION

An overview of intra-arterial neoadjuvant chemotherapy of head and neck is presented. Knowledge of cell cycle processes, especially apoptosis and repair of damaged DNA, could significantly influence the choice of the therapeutic algorithm and therapeutical effect.

Induction therapy in the modern era of combined-modality therapy for locally advanced head and neck cancer

As therapy for locoregionally advanced head and neck cancer (HNC) has evolved, treatment has become increasingly aggressive and cure rates have risen. However, survival still remains poor. The evolving standard of care has focused on the concurrent use of chemotherapy with more aggressive radiotherapy; however, patients continue to recur locally and/or regionally, albeit at a diminished rate, and distant metastases have become a major site of fatal recurrence, while long-term local and acute systemic toxicities have increased. As a result of these changes in outcomes and a re-evaluation of earlier historical data by meta-analyses, interest in cisplatin and 5-fluorouracil (PF) induction chemotherapy has re-emerged and evolved. Most recently randomized studies comparing PF with PF plus a taxane, in particular docetaxel (TPF regimen), have demonstrated markedly superior survival with the three-drug regimens. TPF is now considered the standard of care for induction chemotherapy. Induction chemotherapy followed by chemoradiotherapy, known as sequential therapy, has been shown to be safe and effective. This approach is promising and may have a survival advantage over chemoradiotherapy alone. Both TPF induction and sequential therapy are considered appropriate platforms upon which the new molecularly targeted agents can be tested.

Intracranial Head and Neck Tumors: Endovascular Considerations, Present and Future

TO REVIEW THE literature on endovascular therapies available to clinicians to aid in the management of head, neck, and intracranial tumors. Hypervascular tumors of the head and neck region, as well as the intracranial region, are associated with large amounts of blood loss intraoperatively. Preoperative embolization of selected hypervascular tumors has been proposed in the literature as a method of reducing blood loss intraoperatively. This technique involves superselective catheterization of the feeding arteries to the tumor bed and then by infusion of embolic particles to saturate the tumor bed in the hopes of inducing necrosis. For less vascular tumors, selective infusion of chemotherapeutic agents has been reported as a method of reducing the systemic toxic effects of these medications. Endovascular therapies for hypervascular and less vascular tumors hold promise, although multicenter randomized controlled trials are required to help identify the patients that will benefit the most.

5-Fluorouracil-cisplatin adducts with potential antitumor activity

Using 5-fluorouracil (5-FU) and cis-diamminedichloroplatinum(II) (cisplatin, CDDP) as starting compounds, 5-FU-cisplatin adducts cis-[Pt(NH(3))(2)(HFU)Cl] (1) and cis-[Pt(NH(3))(2)(HFU)(2)] (2) were prepared. The obtained complexes were characterized by IR, ES-MS and 1H NMR spectroscopy. Complex 1 reacted with guanosine-5'-monophosphate (5'-GMP) and gave rise to a stable mixed-ligand complex cis-[Pt(NH(3))(2)(HFU)(GMP)] (3), whereas 2 did not undergo a similar reaction. In vitro cell growth inhibition tests of complexes 1 and 2 exhibited moderate antitumor activities against the melanoma B16-BL6 cell line. This work provides the basis for a potential alternative for the combinational use of 5-FU and CDDP in cancer therapy.

Phase II study of induction chemotherapy with paclitaxel, ifosfamide, and carboplatin (TIC) for patients with locally advanced squamous cell carcinoma of the head and neck

BACKGROUND

This Phase II trial was conducted to determine the response rate, particularly of the primary sites, tolerability, and toxicity of induction chemotherapy of paclitaxel, ifosfamide, and carboplatin for patients with previously untreated locally advanced squamous cell carcinoma of the head and neck (SCCHN). We also hypothesized that improved complete response (CR) rates with the induction chemotherapy may render better survival rates with subsequently delivered definitive local treatment.

METHODS

All eligible patients with locally advanced SCCHN received two courses of induction chemotherapy and underwent repeated head and neck examination and computed tomography or magnetic resonance imaging scans. If the patients achieved responses (CR or partial [PR]), they received two more courses of chemotherapy before undergoing definitive local treatment. Induction chemotherapy consisted of paclitaxel (T; 175 mg/m(2) in a 3-hour infusion) on Day 1, ifosfamide (I; 1000 mg/m(2) in a 2-hour infusion) on Days 1-3 with intravenous mesna (200 mg/m(2) before and 400 mg/m(2) after ifosfamide), and carboplatin (C) using the Calvert formula for the area under the plasma concentration-versus-time curve of 6 on Day 1, repeated every 3-4 weeks. Prophylactic hematopoietic growth factors or antibiotics were not used in this study. Definitive local treatment was given based on the investigators' preference.

RESULTS

Fifty-four patients were registered and 52 patients were assessable for response to induction chemotherapy; 2 were not evaluable. After four courses of induction chemotherapy, the CR rates of the primary and lymph node sites were 60%, and 41%, respectively. For both primary and lymph node sites, there were 31% CRs and 50% PRs with an overall response rate of 81%. Five (9%) patients developed neutropenic fever, all of whom recovered with antibiotic therapy. Two (4%) patients had infection without neutropenia and recovered without any complication. Grade 3/4 thrombocytopenia and anemia occurred in three (6%) and four (7%) patients, respectively. Grade 3/4 fatigue developed in four (7%), arthralgia/myalgia in two (4%), peripheral neuropathy in two (4%), and orthostatic hypotension in two (4%) patients. One patient died of severe anaphylaxis although a maximized resuscitation effort was made. With a median follow-up of 22 months, the organ preservation rate was about 81% (42 of 52 patients). Although survival rates were not primary end points in this study, with a median follow-up of 22 months, 43 (83%) patients are still alive. Overall 1 and 2-year survival rates were 88% and 82%, respectively. Disease-free 1 and 2-year survival rates were 88% and 77% respectively.

CONCLUSIONS

TIC induction chemotherapy is associated with a high CR rate at the primary sites and with excellent survival and organ preservations rates with subsequently delivered definitive local therapy. The regimen was also well tolerated in the majority of patients. The TIC regimen should be developed further in the context of induction chemotherapy followed by concomitant chemoradiotherapy or with specific molecular targeted agents.

Multicenter phase I-II trial of docetaxel, cisplatin, and fluorouracil induction chemotherapy for patients with locally advanced squamous cell cancer of the head and neck

PURPOSE

We conducted a phase I-II, multi-institutional trial to determine the maximum-tolerated dose (MTD) of cisplatin in an induction chemotherapy regimen of docetaxel, cisplatin, and fluorouracil for squamous cell cancer of the head and neck (SCCHN) and to determine the safety, tolerability, and efficacy of the regimen at MTD.

PATIENTS AND METHODS

A total of 43 patients with previously untreated, locally advanced, curable SCCHN were entered. Overall, 29 patients (67%) had N2 or N3 nodal disease and nine (21%) had T4 primary tumors. All patients received docetaxel 75 mg/m(2) on day 1; cisplatin at 75 (level I) or 100 (level II) mg/m(2) on day 1; and a continuous fluorouracil infusion at 1,000 mg/m(2)/d on days 1 through 4. Patients were treated with prophylactic antibiotics on days 5 through 15. Cycles were repeated every 21 days for a total of three cycles. Patients then received definitive therapy based on institutional preferences.

RESULTS

Thirteen patients were treated at level I, and 30 patients were treated at level II. All 43 patients were assessable for toxicity. There were no major differences in toxicity between level I and level II. Cisplatin-associated grade 3 or 4 hypomagnesemia or hypocalcemia occurred in 13 (30%) and hearing loss in two patients (5%). Grade 3 or 4 neutropenia was observed in 41 patients (95%) and febrile neutropenia occurred in eight (19%). There was one serious infection (2%). There were 17 (40% [95% confidence interval [CI], 25% to 56%]) clinical complete responders (CR), 23 (54% [95% CI, 39% to 69%]) partial responders (PR), one (2%) with no change, and two (5%) unassessable patients. Major responses (CR, PR) were observed in 40 (93% [95% CI, 81% to 99%]) patients. Primary site CR was documented in 24 (54%) of patients. Postchemotherapy primary site biopsies were performed in 25 patients (58%) and pathologically negative biopsy was obtained in 11 (92%) of 12 primary site clinical CRs and seven (54%) of 13 with PR or no change. Overall, negative biopsies were obtained in 18 patients (72%).

CONCLUSION

TPF induction chemotherapy can be delivered safely with a cisplatin dose of 100 mg/m(2) in previously untreated patients with SCCHN. The regimen is associated with a high rate of primary site clinical and pathologic CRs. Phase III comparison with cisplatinum and fluorouracil chemotherapy is warranted.

Phase II trial of intratumoral administration of ONYX-015, a replication-selective adenovirus, in patients with refractory head and neck cancer

PURPOSE

To determine the safety, humoral immune response replication, and activity of multiple intratumoral injections of ONYX-015 (replication selective adenovirus) in patients with recurrent squamous cell carcinoma of the head and neck (SCCHN).

PATIENTS AND METHODS

This phase II trial enrolled patients with SCCHN who had recurrence/relapse after prior conventional treatment. Patients received ONYX-015 at a dose of 2 x 10(11) particles via intratumoral injection for either 5 consecutive days (standard) or twice daily for 2 consecutive weeks (hyperfractionated) during a 21-day cycle. Patients were monitored for tumor response, toxicity, and antibody formation.

RESULTS

Forty patients (30 standard and 10 hyperfractionated) received 533 injections of ONYX-015. Standard treatment resulted in 14% partial to complete regression, 41% stable disease, and 45% progressive disease rates. Hyperfractionated treatment resulted in 10% complete response, 62% stable disease, and 29% progressive disease rates. Treatment-related toxicity included mild to moderate fever (67% overall) and injection site pain (47% on the standard regimen, 80% on the hyperfractionated regimen). Detectable circulating ONYX-015 genome suggestive of intratumoral replication was identified in 41% of tested patients on days 5 and 6 of cycle 1; 9% of patients had evidence of viral replication 10 days after injection during cycle 1, and no patients had evidence of replication > or = 22 days after injection.

CONCLUSION

ONYX-015 can be safely administered via intratumoral injection to patients with recurrent/refractory SCCHN. ONYX-015 viremia is transient. Evidence of modest antitumoral activity is suggested.

Effect of consecutive lower-dose cisplatin in enhancement of 5-fluorouracil cytotoxicity in experimental tumor cells in vivo

It is known that cisplatin (CDDP) potentiates the cytotoxicity of 5-fluorouracil (5-FU), and that the biochemical mechanism is an increase in the intracellular reduced folate levels in the tumor cells. We investigated the effect of consecutive administration with lower-dose CDDP on intracellular accumulation of reduced folate and the activity of methionine synthase, a key enzyme in intracellular methionine synthesis. When CDDP (1 mg/kg) was administered i.p. to ascitic Yoshida sarcoma-bearing rats for 4 consecutive days, both the reduced folate levels and methionine synthase activity in the cells significantly increased, as the same as a single 5 mg/kg dose of CDDP. Furthermore, when Yoshida sarcoma-bearing rats were pre-treated with 1 mg/kg CDDP for 5 consecutive days, [14C]L-methionine incorporation into the isolated ascitic cells was significantly inhibited as compared to that in non-treated cells, suggesting that consecutive administration of lower-dose CDDP is capable of inducing the intracellular modulation of reduced folate levels and methionine synthase activity via inhibition of cellular uptake of methionine. In addition, 5-day administration of lower-dose (1 mg/kg) CDDP potentiated the antitumor effect of 5 mg/kg S-1, a new oral preparation of tegafur, given for 7 consecutive days, and this combined effect was almost similar to the antitumor effect of a combination of S-1 and a single conventional dose (5 mg/kg) of CDDP. Consecutive lower-dose CDDP also may be concluded to act as an important modulator of the enhancement of 5-FU cytotoxicity in experimental tumors.

a controlled trial of intratumoral ONYX-015, a selectively-replicating adenovirus, in combination with cisplatin and 5-fluorouracil in patients with recurrent head and neck cancer

ONYX-015 is an adenovirus with the E1B 55-kDa gene deleted, engineered to selectively replicate in and lyse p53-deficient cancer cells while sparing normal cells. Although ONYX-015 and chemotherapy have demonstrated anti-tumoral activity in patients with recurrent head and neck cancer, disease recurs rapidly with either therapy alone. We undertook a phase II trial of a combination of intratumoral ONYX-015 injection with cisplatin and 5-fluorouracil in patients with recurrent squamous cell cancer of the head and neck. There were substantial objective responses, including a high proportion of complete responses. By 6 months, none of the responding tumors had progressed, whereas all non-injected tumors treated with chemotherapy alone had progressed. The toxic effects that occurred were acceptable. Tumor biopsies obtained after treatment showed tumor-selective viral replication and necrosis induction.

A phase II trial of palliative docetaxel plus 5-fluorouracil for squamous-cell cancer of the head and neck

PURPOSE

A phase II study to determine the response rate and toxicity of docetaxel and 5-fluorouracil (5-FU) every four weeks ('TF'), in patients with incurable SCCHN.

PATIENTS AND METHODS

Patients with metastatic or recurrent SCCHN with an ECOG PS < 3 were enrolled in an institutional review board approved trial. Prior induction or adjuvant chemotherapy was permitted provided six months had elapsed. The regimen was docetaxel 70 mg/m2 i.v., day 1 and 5-FU 800 mg/m2/d x 5 days, days 1-5, as a continuous intravenous infusion, repeated every 28 days. Planned intra-patient dose modifications were based on hematological, cutaneous, and gastrointestinal toxicities. Patients were removed from the study for progression of disease or unacceptable toxicity.

RESULTS

Seventeen patients were enrolled. Fourty-six cycles of TF were administered. Reasons for discontinuance of TF included: progressive disease, 12 patients; toxicity, 3 patients; concomitant illness, 1 patient; death, 1 patient. The most common toxicities were neutropenia, mucositis, anemia, fatigue, alopecia, pain, diarrhea and nausea. Evaluation of responses to TF showed that there were four patients of seventeen (24%, 95% exact CI: 6.8-49.9) who achieved a PR or CR. Accrual was terminated after interim analysis of the response rate of the first 17 patients failed to exceed 4 of 17.

CONCLUSIONS

The response rate to TF in patients with SCCHN was lower than expected. Trials of other regimens should take precedence over further exploration of the TF regimen.

"Decadose" effects of cisplatin on squamous cell carcinoma of the upper aerodigestive tract. II. Clinical studies

There is evidence that solid tumors rapidly acquire cellular resistance to cisplatin. This resistance is usually mild to moderate and could be circumvented with higher concentrations of drug exposure if ancillary methods were available to avoid systemic cytotoxicity. The purpose of this study was to determine whether a tenfold increase in dose (decadose) would overcome cisplatin resistance. In a clinical trial, response effects of cisplatin at dose intensities ranging from 32.5 to 200 mg/m2 per week, which were delivered by highly selective intra-arterial infusions with a simultaneously administered intravenous neutralizing agent, were measured in 31 patients with squamous cell carcinoma (SCC) of the upper aerodigestive tract (UADT). The overall response rate (complete response [CR] and partial response [PR] to cisplatin therapy at dose intensity intervals of 0 to 74, 75 to 149, and 150 to 200 mg/m2 per week were 45.5%, 72.7%, and 100%, respectively. The average received dose intensities for nonresponders and responders (CR and PR) were 57.8 and 120.7 mg/m2 per week, respectively (P = .031). The results indicate that resistance to standard doses of cisplatin by SCC of the UADT, both previously untreated and recurrent, can be substantially overcome with "decadose" cisplatin therapy. Progress toward improving survival of patients with head and neck cancer, and possibly other site-specific malignancies, may be achieved by incorporating decadose cisplatin therapy into a multimodality treatment plan.

Modified combination chemotherapy of cisplatin and 5-fluorouracil in squamous cell carcinomas of the head and neck

Randomized studies on the efficacy of two courses of different types of chemotherapy, including cisplatin and 5-fluorouracil (5-FU), were performed on 130 previously untreated cases with advanced squamous cell carcinomas of the head and neck. Cisplatin, followed by 120-hr continuous 5-FU infusion given in the conventional way, was administered to 60 patients (Group A), while cisplatin was administered 72 hr after the initiation of continuous 5-FU infusion in 70 other patients (Group B). The overall response rates (complete response plus partial response) were 58% in group A and 69% in group B, respectively. A superior complete response rate was obtained in cases receiving modified chemotherapy (10% in group A vs 20% in group B). There was no significant difference in the incidence of side effects between the two groups. These findings indicate that the modified cisplatin plus 5-FU combination chemotherapy tested here is more efficacious regimen than that of the conventional one to achieve high complete response rate and subsequently, to improve the survival of advanced carcinoma cases of the head and neck.

Metabolic basis of the synergistic antitumor activities of 5-fluorouracil and cisplatin in rodent tumor models in vivo

The biochemical mechanism of the synergy of 5-fluorouracil (FUra) and cisplatin (CDDP) was studied using transplantable tumors in rodents in vivo. The reduced folate 5,10-methylenetetrahydrofolate (CH2FH4) and its precursor tetrahydrofolate (FH4) are essential cofactors for the formation of a tight ternary complex of thymidylate synthase (TS) and 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) derived from FUra. Intraperitoneal administration of CDDP (5 mg/kg) inhibited the incorporation of exogenous L-methionine into ascitic tumor cells and increased the levels of CH2FH4 and FH4 in ascitic Yoshida sarcoma and P-388 cells transplanted into rats and mice to levels about 2-3 times those measured in cells from animals that were not treated with CDDP. Preincubation with 10(-6) M FUra in Hanks' medium inhibited [6-3H]-2'-deoxyuridine incorporation into DNA of tumor cells from CDDP-treated rats 3 times more than that into cells from untreated rats, indicating that the inhibition of TS by FdUMP derived from FUra was enhanced in the presence of CH2FH4. Intraperitoneal administration of CDDP on day 1 and continuous infusion of FUra from day 1 to day 6 had synergistic effects in inhibiting tumor growth in Yoshida sarcoma-bearing rats. Oral administration of UFT, a combined form of 1 M tegafur and 4 M uracil, for 7 consecutive days beginning at 24 h after tumor implantation and a single i.p. injection of CDDP on day 1 had a significantly greater effect than did either agent alone. These results suggest that CDDP significantly enhances FUra cytotoxicity by inhibiting intracellular L-methionine metabolism and consequently increasing the reduced folate pool in mammalian tumor models in vivo.

A phase I study of prolonged infusion 5-fluorouracil and concomitant radiation therapy in patients with squamous cell cancer of the head and neck

The radiosensitization properties of 5-FU are well documented, and clinical trials have suggested improved local control and survival in head and neck cancer. Clinical trials to date have used bolus injection or short term (less than or equal to 5 days) 5-FU infusions. To determine the maximum tolerated dose (MTD) of 5-FU given as continuous intravenous infusion for 12 weeks concomitant with conventional radiation therapy, 18 patients with advanced inoperable head and neck cancers were treated with conventional irradiation and 100, 200, 250, or 300 mg/m2/day of 5-FU. A dose of 250 mg/m2/day was determined to be the maximum tolerated dose and is recommended for Phase II studies.

A phase I trial of cisplatin in hypertonic saline and escalating doses of 5-fluorouracil by continuous intravenous infusion in patients with advanced malignancies

Thirty-four patients with incurable solid tumors were treated in a Phase I trial with a fixed dose of high-dose cisplatin (CDDP) administered in hypertonic saline and escalating doses of infusional 5-fluorouracil (5-FU). Five treatment levels of 5-FU, ranging from 500 to 900 mg/m2/day for 5 days, were studied. Leukopenia, thrombocytopenia, and oral mucositis were the dose-limiting toxicities encountered. Nephrotoxicity was minimal. Ototoxicity and peripheral neuropathies were rare and mild in this patient group, but most patients received only a small number of treatment cycles. Diarrhea was not dose-limiting. Two complete responses (one non-small cell lung cancer and one sweat gland carcinoma) were observed. No other major responses were noted. With the dose of CDDP set at 35 mg/m2/day for 5 consecutive days, the maximum tolerated dose (MTD) of a concurrent 5-day 5-FU infusion was found to be 900 mg/m2/day. The recommended dosages for Phase II trials are 35 mg/m2/day CDDP and 800 mg/m2/day 5-FU for 5 consecutive days. Cancers of the lung, breast, gastrointestinal tract, and genitourinary tract would be reasonable targets for Phase II studies.