Phase Ib Study of PEGylated Recombinant Human Hyaluronidase and Gemcitabine in Patients with Advanced Pancreatic Cancer

PURPOSE

This phase Ib study evaluated the safety and tolerability of PEGylated human recombinant hyaluronidase (PEGPH20) in combination with gemcitabine (Gem), and established a phase II dose for patients with untreated stage IV metastatic pancreatic ductal adenocarcinoma (PDA). Objective response rate and treatment efficacy using biomarker and imaging measurements were also evaluated.

EXPERIMENTAL DESIGN

Patients received escalating intravenous doses of PEGPH20 in combination with Gem using a standard 3+3 dose-escalation design. In cycle 1 (8 weeks), PEGPH20 was administrated twice weekly for 4 weeks, then once weekly for 3 weeks; Gem was administrated once weekly for 7 weeks, followed by 1 week off treatment. In each subsequent 4-week cycle, PEGPH20 and Gem were administered once weekly for 3 weeks, followed by 1 week off. Dexamethasone (8 mg) was given pre- and post-PEGPH20 administration. Several safety parameters were evaluated.

RESULTS

Twenty-eight patients were enrolled and received PEGPH20 at 1.0 (n = 4), 1.6 (n = 4), or 3.0 μg/kg (n = 20), respectively. The most common PEGPH20-related adverse events were musculoskeletal and extremity pain, peripheral edema, and fatigue. The incidence of thromboembolic events was 29%. Median progression-free survival (PFS) and overall survival (OS) rates were 5.0 and 6.6 months, respectively. In 17 patients evaluated for pretreatment tissue hyaluronan (HA) levels, median PFS and OS rates were 7.2 and 13.0 months for "high"-HA patients (n = 6), and 3.5 and 5.7 months for "low"-HA patients (n = 11), respectively.

CONCLUSIONS

PEGPH20 in combination with Gem was well tolerated and may have therapeutic benefit in patients with advanced PDA, especially in those with high HA tumors. Clin Cancer Res; 22(12); 2848-54. ©2016 AACR.

Exploratory biomarker results from early investigation of PEGPH20 in combination with gemcitabine (Gem) in patients with pancreatic cancer (PDA)

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Background: PEGPH20 (PEG), a PEGylated recombinant human hyaluronidase, has anti-tumor activity as a single agent and in combination with chemotherapy in preclinical models. A Phase 1b study of PEG + Gem (P+G) in patients (pts) with advanced PDA showed good anti-tumor activity, particularly in pts with HAhigh tumors (ECCO 2013). In this study, we investigated pharmacodynamic (PD) markers including plasma(soluble) HA (sHA), dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and 18Fluorodeoxyglucose positron emission tomography (PET/CT) to explore additional correlates for PEG activity. Methods: 28 pts with stage IV PDA were treated with PEG at 1, 1.6, or 3µg/kg IV twice weekly for Wks 1-4 and Wks 5-7, followed by 1 wk rest, plus Gem at 1000 mg/m2 IV once weekly for Wks 1-7, then 1 wk rest. Thereafter, P+G was given once weekly for 3 wks in 4-wk cycles. Serial plasma samples were collected and analyzed in a quantitative assay for PEG and sHA. Exploratory imaging by DCE-MRI was performed on selection pts at baseline, 8hr, 24hr and end of cycle 1, PET/CT was performed at baseline and at the end of each cycle. Results: PEG pharmacokinetics was well-characterized by a 2-compartment PK model, peak plasma concentration increased in a dose-proportional manner after a single or repeat administration of PEG. Dose- and time-dependent increases in sHA were observed within 2-3 days after 1.0, 1.6, or 3.0 µg/kg of PEG administration. The median peak concentrations were 3,736; 48,150; and 74,950ng/mL, respectively, and increased with increasing doses. sHA reached steady state approximately 1 wk after repeated PEG administration, consistent with the expected hyaluronidase activity of PEG. Exploratory analysis with DCE-MRI from 6 pts showed an early increase (24hrs) in tumor perfusion (Ktrans) in target lesions. PET/CT from 5 pts showed an average reduction in the maximum standardized uptake value (SUVmax) of 37% at EOC1, and partial metabolic responses using EORTC criteria were achieved in 4 of 5 pts. These results suggest that P+G has measurable biological activity in metastatic PDA Conclusions: Plasma sHA concentration, DCE-MRI and PET/CT are PD markers for evaluation of P+G activity.

Final results of a phase Ib study of gemcitabine plus PEGPH20 in patients with stage IV previously untreated pancreatic cancer

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Background: Poor outcome in pancreatic cancer (PDA) has been associated with tumor stroma limiting access of chemotherapy drugs. PEGPH20 (PEG), PEGylated recombinant human hyaluronidase, which depletes hyaluronan (HA) in tumors, has demonstrated anti-tumor activity in preclinical PDA models. In a KPC model of PDA, PEG + gemcitabine (Gem) significantly prolonged survival compared to Gem alone. In Phase 1 PEG monotherapy studies, the MTD was 3µg/kg. The most common adverse events (AEs) were musculoskeletal events. Methods: This was a phase 1b study to determine the recommended phase 2 dose of PEG + Gem in patients (pts) with previously untreated Stage IV pancreatic cancer. PEG was given at 1, 1.6, or 3µg/kg IV twice weekly Wks 1–4 and weekly Wks 5–7, followed by 1 wk rest. Gem was given at 1000mg/m2IV once weekly for Wks 1–7, then 1 wk rest. Thereafter, PEG + Gem were given once weekly for 3 wks in 4-wk cycles. Dexamethasone was given pre and post PEG doses. Due to evolving SOC, the study was discontinued before initiation of the phase 2 randomization. Results: Twenty-eight pts were enrolled in the study. The majority of the patients (89%) had metastatic sites in the liver. Four, 4 and 20 pts received PEG at 1, 1.6 and 3µg/kg, respectively. The most common AEs related to PEG were muscle spasm (54%), myalgia (39%), arthralgia (29%), peripheral edema (29%), fatigue (25%), and extremity pain (18%). Median progression free survival (PFS) and overall survival (OS) were assessed and were 154 and 200 days, respectively. In an exploratory analysis, tumor biopsies from 17 pts were evaluated for HA levels (HAhigh or HAlow). 6 pts were determined to have HAhigh tumors and 11 pts had HAlow tumors. The median PFS and OS for HAhigh pts were 219 days (95% CI: 159-276) and 395 days (95% CI: 210-578). For HAlowpts median PFS and OS were 108 (95% CI: 14-163) and 174 days (95% CI: 34-293). Conclusions: PEG + Gem is generally well tolerated in advanced pancreatic cancer and shows promising clinical activity, especially in pts with HAhigh tumors. ClinicalTrials.gov Identifier: NCT01453153.

[Combined treatment of patients with locally advanced rectal cancer]

The objective of this study was to improve the immediate and long-term results of combined treatment of patients with locally advanced rectal cancer. The study included 128 patients with morphologically confirmed diagnosis and clinical stage cT3/T4 and N-/N+, treated from 1998 to 2009. The comparison group had 64 patients, combined treatment included prolonged preoperative radiotherapy 4 Gy and 40 Gy, surgery was performed after 4 weeks. In the study group--also 64 patients--combined treatment consisted of preoperative chemoradiotherapy (continuous a-120 hour infusion of 5-fluorouracil at a dose of 500 mg/m2 in the first and last week of radiotherapy in 2 Gy to 50 Gy), surgery was performed through 6 weeks after chemoradiotherapy. Excision of the primary tumor was performed in 40 (62.5%) patients in the control group and in 53 (82.8%) patients in the study group. Wherein R-0 resections were performed in 32 (67%) patients and in 41 (73%), and R-1 resections--in 1 (2%) patients, and 7 (13%) patients in the control and study groups respectively. A 5-year survival rate was 43.6 ± 7.2% control and 62.7 ± 5.1 % in the study group.

[The distal resection margin in rectal cancer surgery]

Spread of the tumor in the distal direction is an important factor that must be considered when performing organ-serving surgery for rectal cancer. Particular relevance it has acquired in recent years due to the general tendency to expand the indications for the preservation of natural reflex-apparatus in patients with medium- and lower-ampullar part of the rectum.

[Pathomorphism of rectal cancer during neoadjuvant chemoradiotherapy]

The pathomorphism of rectal cancer (RC) was studied in 99 patients who received neoadjuvant chemoradiotherapy using two drugs (5-fluorouracil and xeloda). A morphological study indicated the qualitatively similar manifestations of pathomorphism (tumor necrosis, inflammation, and sclerosis) which were more pronounced in the use of xeloda. Three degrees of the pathomorphism of RC have been identified: the tumor was unchanged, changed, and undetectable.

A phase Ib study of gemcitabine plus PEGPH20 (pegylated recombinant human hyaluronidase) in patients with stage IV previously untreated pancreatic cancer

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Background: PEGPH20 is a PEGylated version of human recombinant hyaluronidase. In preclinical studies, PEGPH20 depleted pancreatic cancers of their high hyaluronan (HA) content. In a genetically-engineered murine model of PDA, PEGPH20 + gemcitabine (Gem) significantly prolonged survival compared to Gem alone. In Ph1 PEGPH20 monotherapy studies, the MTD was 3.0 μg/kg. The most common AEs were musculoskeletal events (MSEs). Methods: This was a dose-escalation study to find the recommended Phase 2 dose (RP2D) of PEGPH20 in combination with Gem in patients (pts) with Stage IV previously untreated pancreatic cancer. Pts received PEGPH20 at 1, 1.6, or 3 μg/kg IV twice a week for Wks 1-4, weekly for Wks 5-7, then 1 wk rest. Dose escalation was based on safety. Gem was given at 1000 mg/m2 IV once a week for Wks 1-7, then 1 wk rest. Thereafter, PEGPH20 + Gem were given once a week for 3 wks in 4-wk cycles. Dexamethasone was given pre and post PEGPH20 doses. Results: Of the 28 pts enrolled, the majority had a Karnofsky performance status of 80%, and 85%/19%/26% of pts had liver/lung/visceral metastases. The median age was 58 yrs. Four pts received PEGPH20 at 1 μg/kg, 4 at 1.6 μg/kg, and 20 at 3 μg/kg. The RP2D was 3 μg/kg. Treatment duration ranged from 1-274 days; 5 pts remain on study. Treatment was generally well tolerated. Ten pts had 1 Gem dose reduction, 2 pts had 1 PEGPH20 dose reduction (3 to 1.6 µg/kg), but no pt had a DLT. The most common PEGPH20-related AEs were MSEs (25% Gr1; 18% Gr2) and fatigue (21% Gr1; 11% Gr2). Objective response was assessed by an independent central radiologist using RECIST 1.1. Of the 21 pts evaluable for efficacy, 7 had partial response (PR) for an overall response rate (ORR) of 33%, and 9 had stable disease for ≥ 2 mo. Tumor biopsies from 12 pts were evaluable for HA staining. HA was high in 9 and low in 3. Of the 9 with high HA staining, 5 had PR (56% ORR); HA data were not available for the other 2 PR pts. PK results show dose-dependent exposure consistent with data from PEGPH20 monotherapy studies. Conclusions: PEGPH20 in combination with Gem is generally well tolerated in advanced pancreatic cancer and shows promising efficacy, especially in pts with high intratumoral HA content. Clinical trial information: NCT01453153.

Pharmacokinetic (PK)/pharmacodynamic (PD) results from a phase Ib study of pegylated hyaluronidase PH20 (PEGPH20) in combination with gemcitabine (Gem) in patients with pancreatic cancer

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Background: Enzymatic degradation of hyaluronan (HA) is a novel strategy to target the desmoplastic stroma of pancreatic cancer. PEGPH20, a pegylated form of recombinant human hyaluronidase PH20, is an investigational drug in clinical trials. Preclinical studies demonstrate that sustained HA removal by PEGPH20 inhibits tumor growth and enhances chemotherapeutic activity in HA-rich xenografts and genetically engineered mouse tumor models. Ph1 PEGPH20 monotherapy studies show increased tumor perfusion by DCE-MRI, metabolic partial responses by FDG-PET, and stromal remodeling in tumor biopsies from selected advanced cancer patients (pts). Methods: This was a dose-escalation study to find the recommended Ph2 dose of PEGPH20 in combination with Gem in pts with Stage IV previously untreated pancreatic cancer. Pts received Gem at 1000 mg/m2 IV qwk for Wks 1-7 plus PEGPH20 at 1, 1.6, or 3 μg/kg IV twice a week for Wks 1-4 and qwk for Wks 5-7. Wk 8 was a rest week. Thereafter, PEGPH20 + Gem were given qwk for 3 wks in 4-wk cycles. Serial plasma samples were collected and hyaluronidase activity measured by an ultrasensitive assay to assess PEGPH20 exposure. Plasma HA catabolites were measured by quantitative HPLC to assess PD. Results: 28 pts were enrolled. Plasma PEGPH20 concentrations were proportional to dose, and kinetics were well-characterized by a 2-compartment PK model. Estimates for clearance (0.5-2 mL/hr/kg) were consistent with long t1/2 (1-2 days) previously seen with single-dose PEGPH20 monotherapy. Wks 1 and 4 PK profiles were similar, suggesting no changes to PEGPH20 clearance mechanisms after multiple doses or effects of Gem on PEGPH20 exposure. Most pretreatment plasma HA levels were <1 μg/mL and increased in a time- and dose-dependent manner after dosing. Circulating HA concentration was >500 µg/mL in several pts given 3 μg/kg PEGPH20. Conclusions: PEGPH20 plasma levels can be predicted using a linear PK model and circulating HA catabolites can be used as a quantitative measure of PEGPH20 PD. Results are consistent with the mechanism of action of hyaluronidase and support further study of PEGPH20 with anticancer agents. Clinical trial information: NCT01453153.

[The influence of lymphadenectomy on the results of the gastric cancer treatment]

Results of randomized studies and meta-analyses of the long-term results of surgical treatment of the gastric cancer with lymphadenectomy were compared. The D2 lymphadenectomy permits low indices of postoperative morbidity and mortality. The further lymphadenectomy volume increase does not lead to the significant improvement of the long term treatment results. The splenectomy and pancreas resection are not obligatory by the gastric cancer treatment and should be performed only by certain indications. The prevailing volume of surgical resection is considered to be gastrectomy; the indications to the subtotal gastric resection should be limited for the reduction of the local recurrence rate. Thereby, the optimal algorithm of the gastric cancer treatment includes the gastrectomy and D2 lymphadenectomy, accomplished by the neo- and adjuvant chemotherapy.

[D2 lymphadenectomy for surgical and combined treatment of the gastric cancer]

Immediate results of 100 D2 lymphadenectomies, performed for gastric cancer, were analyzed. The combined treatment included preoperative radiotherapy (n=39), combinations of pre- and postoperative radiotherapy (n=18) and adjuvant chemotherapy (n=18). The majority of patients had tumors of the lower third of the stomach, histologically low- and non-differentiated adenocarcinomas. Gastrectomy was performed in majority of cases. Achieved results showed, that pre- and postoperative radiotherapy led neither to lethality nor to complication rate or to hospital stay time increase. Thus, D2 lymphadenectomy for surgical and combined treatment of the gastric cancer, is a safe procedure with an acceptable rate of postoperative complications. It does not prevent neo- and adjuvant chemo- or radiotherapy conduction. D2 lymphadenectomy allows a more thorough cancer staging, according both to international and Japanese classifications.

[Clinico-morphological parallels among stomach cancer patients]

The paper reports the demographic and clinical data on more than 1,100 stomach cancer patients who underwent radical surgery in 1970-2007. Significant changes in structure and histological pattern of that pathology and primarily the growing fraction of signet ring and undifferentiated cell cancer (30%) are evident. It was matched by similarly important changes in the demographic and clinical data on patients with different morphological patterns and extent of tumor cell differentiation. Precise correlations between morphological pattern and loco-regional extent, site, size, pattern of growth and polyneoplasia rate were identified. Such characteristics should be taken into account when devising diagnostic and therapeutic strategies.

[Effect of morphologic features on recurrence and metastasis in stomach cancer]

Data on examination of 192 patients radically operated for stomach cancer at the Center's Clinic were analyzed vis-a-vis postoperative recurrences. Marked dependence of metastatic spread features and pathway on histological pattern of tumor was established. This can be used in working out therapeutic strategies. Most patients revealed different patterns of relapse. High incidence of peritoneal tumorigenesis unaccompanied by invasion of serous membrane was reported patients with primary signet-cell and undifferentiated cell tumor among others. Considering high frequency of local relapse in signet-cell and mixed cell cancer, gastrectomy should be regarded as operation of choice irrespective of site and size of tumor.

[Comparative analysis of long-term results of combined and surgical treatment at the patients with signet ring cell carcinoma of stomach]

Overall 194 patients with signet ring cell carcinoma of stomach were treated, 124 (64%) of them underwent combined treatment (preoperative radiotherapy with subsequent operation), 70 (36%) - only surgical treatment. There were no differences in survival rate between two groups at early (pT1) cancer. The combined method has advantages over isolated surgical at T2 tumors (both with and without regional lymphatic metastases) and at T3 tumors without regional lymphatic metastases (p=0.03). At T3N1-2 tumors with regional lymphatic metastases and T4 tumor neither combined no surgical method demonstrated positive results of treatment. Generally combined treatment with preoperative radiotherapy has statistically significant advantage (p=0.007) over surgical treatment at the patient with signet ring cell carcinoma of stomach.

[Comparative analysis of long-term results of combined and surgical treatment in gastric cancer]

The end-results of combined and surgical treatment of gastric cancer are compared. Survival rates were sufficiently high in both procedures in cases without extension through the serosa (T1-2) or regional metastases with adenocarcinoma cells were well differentiated (NO). However, combined treatment proved more effective in cases of the opposite situations (p=0.04-0.0001). Considering the possibility of inadequate staging, the following indications for preoperative radiotherapy are suggested: low cell differentiation, signet-cell or undifferentiated gastric tumor of 3-10 cm in diameter. In other words, early cancer of the stomach and total involvement must be excluded.

[Regularities of relapse and metastasis of signet ring cell carcinoma of the stomach following combined and surgical treatment]

Characteristics of recurrence and metastatic development of signet ring cell carcinoma of the stomach were studied in 59 cases after combined and surgical treatment. Peritoneal dissemination appeared to be the most frequent pattern of tumor progression. It accounted for 55% of all relapses and occurred in 27% of patients even without extension through serous membrane (pT2). Metastasizing through the lymphatic viae was fairly frequent mostly in cases of peritoneal carcinomatosis while blood flow-related dissemination was not. Subtotal resection in patients with early-stage signet ring cell carcinoma (pT1) was justified because local recurrences are extremely rare in that pathology. Since (pT2-4) stump relapse is fairly frequent (14-16%), the operation of choice was gastrectomy, whatever site of tumor. Regional metastasis recurrence was 20% among patients with relapsing tumor. It usually co-occurred with distant metastases and, therefore, was less clinically significant. However, when concomitant with local recurrence, it ruled out radical treatment. Preoperative radiotherapy was followed by a significant drop in regional metastasis recurrence rate (4.5 and 13.3%, p = 0.04).

[Recurrences after surgical treatment of early (pT1) cancer of the stomach: laws of development, extended lymphadenectomy in prophylaxis of recurrences]

Long-term results of treatment of 175 patients with early cancer of the stomach are analyzed. Recurrences of the disease (local, regional recurrences and distant metastases) were diagnosed in 14 (8.2% of all operated) patients. Duration of recurrence-free period ranged from 2-3 months to 9.5 years; median was 12 months. Tumor spread, regional nodes affection, tumor morphological structure, age of patients were the main prognostic factors for recurrences. Extent of surgery and lymphodissection did not correlate with recurrences rate. It is concluded that extended lymphodissection in patients with early cancer of the stomach should not be regarded as a real method for an increase of treatment efficacy.

[Treatment for primary multiple malignant tumors, a gastric one included]

Cases of primary multiple malignant tumors, with one localized in the stomach, have been studied. In cases of radical surgery, second tumors were detected in 6.2% while in patients with early gastric cancer--twice as many (12.5%). Among second tumors, most frequent were neoplasms of large bowel, urogenital system, head and neck, lung, skin and breast. Radical surgery for gastric cancer was carried out in 94%, palliative resection--6%. Radical surgery for second tumors was performed in 53 (82%), palliative--7 (11%). Surgery for second tumors was used in 38%, combined treatment--27%. Synchronous and, in particular, metachronous tumors were mostly responsible for deaths among those radically treated for stomach cancer. In general, second tumors failed to significantly impact the end results of that pathology (p=0.13). Hence, primary multiple tumors should not be regarded as counterindications for radical treatment, a combined one included, of the either neoplasm, nor does it contribute to postoperative lethality rates. Prior to surgery and during clinical course, it is important to make sure that there are no synchronous or metachronous tumors in sites where they generally occur.

[Comparative assessment of immediate results of combined and surgical treatment of gastric cancer]

The 30-year experience with combined and surgical treatment of gastric cancer gained at the Center is discussed. The results of surgery were improved due to use of intensive preoperative radiotherapy, metronidazole and dynamic fractionated treatment. There was no correlation between intensive preoperative radiotherapy and postoperative complication incidence or lethality, irrespective of extent of surgery or lymph node dissection. Moreover, radiotherapy was followed by a considerable decrease in postoperative incidence of pancreatitis due to inhibition of secretory function by the pancreas. Use of modern technology of radiotherapy planning and implementing left virtually no serious damage. Considering the recent changes introduced to standards for surgical treatment of gastric cancer, our findings point to a safe combination of preoperative radiotherapy with extended surgical and combined treatment.

[Long-term results of pre- and intraoperative radiotherapy in the combined treatment for stomach cancer]

The paper discusses the end results of combined treatment of stomach cancer (radical surgery plus pre- and intraoperative radiotherapy). A randomized evaluation showed that it might be used for loco-regional monitoring. Five-year rates and median of survival rose significantly, as compared with surgery alone, in tumor extension through the stomach wall (T3-4), metastatic dissemination to lymph nodes (N1-2), combinations of such pathologies as well as in cases of low-differentiated, undifferentiated and signet- cell cancer.

[Early cancer of the stomach: pattern of lymphatic metastasizing and its influence on surgical approach]

Results of surgical treatment of 156 patients were analyzed. There were no metastases to the lymph nodes in patients with invasion of mucous membrane only. In patients with invasion of the tumor into a submucous layer regional metastases were revealed in 18 (19%) cases. Number of affected lymph nodes varied from 1 to 7 (2.7, on the average). Metastases to 1 lymph node were revealed in 9 (50%) patients, to 2-3 nodes -- in 5 patients, to 5-7 nodes -- in 4 patients. In 14.78% patients metastases were only to perigastric lymph nodes, in 4 cases -- to nodes of the second level (N2). Invasion of the tumor into submucous layer, location and size of the tumor were the main factor of risk of lymphatic cancer spread. Frequency of lymphatic cancer spread does not exceed 10% in any variant. In patients with proximal tumor, infiltrative growth and size more than 4 cm, tumor lymphatic metastases are diagnosed in each third person. It is concluded that gastrectomy or distal subtotal resection of the stomach with modified D2 lymphatic dissection is the method of choice in treatment of patients with invasion of stomach cancer into submucous layer.

[Cancer of the body of the stomach: comparison of results with surgical and combined therapy]

The immediate and end results of surgical and combined treatment of cancer of the body of the stomach have been evaluated. The combined therapy used intensive preoperative procedures. No significant differences in mortality and postoperative complication rates between combined treatment and surgery were reported. The joint use of preoperative irradiation and radical surgery was followed by better end results in therapy of such locally advanced malignancies as invasion through the stomach wall, metastases to the regional lymph nodes, stage III and infiltrative growth.

[Pre- and intraoperative radiotherapy for locally advanced gastric cancer in conjunction with extended lymph node dissection: results of phase II clinical study]

The paper discusses our findings on a phase II clinical study of an original procedure for therapy of locally advanced gastric cancer including pre- and intraoperative radiotherapy (IORT) and extended lymph node dissection. Out of 24 patients, none had intraoperative complications while postoperative ones developed in 16%; lethality rate was 4%. As far as immediate results are concerned, intensive pre- and intraoperative radiotherapy proved fully compatible with any surgical procedure including extended and extended-combined ones. Survival rates (Kaplan-Meier) were: 1 yr--90 +/- 6%; 2-, 3-year--74 +/- 9%. Indications of adjuvant radiotherapy and approaches to its effective use are discussed.

[Surgical treatment of advanced cancer of the stomach]

Experience in surgical treatment of gastric cancer with distant metastases was analyzed. Distant metastases were located most often in the peritoneum (19 patients), distant lymph nodes (16), liver (10) and ovaries (5). Surgery was performed as gastrectomy (27 patients), subtotal resection of the stomach (25) and extirpation of the gastric stump (4); metastatic tumors were removed in half of the patients. During the last years number of extended gastrectomies increased, but rate of postoperative complications and lethality decreased to 11 and 3.5% respectively. Median of survival was 9.0 months. Cumulative survival was 80% in 6 ms, 39% in 12 ms, 11% in 24 ms. The highest median of survival was in metastatic affection of the lymph nodes (13.7 months), the lowest -- in canceromatosis of the peritoneum (7.1 months). It is concluded that main goal of surgeries is fight with fatal complications of tumors. But today, extended surgeries can be performed in uncomplicated forms of gastric cancer to improve quality of patients' life and to carry out drug therapy more successfully.

Preoperative radiotherapy in combination with metronidazole for resectable gastric cancer: long-term results of a phase 2 study

AIM

Surgery remains the main treatment of stomach carcinoma. Poor long-term survival mandates the study of other techniques. An original treatment scheme with preoperative radiotherapy and metronidazole as a radiosensitizer is reported here.

METHODS

Between 1982 and 1988, MRRC RAMS carried out a prospective clinical trial of preoperative radiotherapy (20 Gy/5 days) in combination with metronidazole (given orally, 3 times, 5 gms per metre(2)). Of 91 patients who received preoperative radiotherapy, 67 patients were operated on with curative intent and were eligible for further analysis.

RESULTS

Acute gastro-intestinal toxicity was significant but manageable without surgery delay in most cases. There were 4 postoperative deaths. Overall 5-year, 10-year survival and median survival were 46%, 36% and 46 months. Serosal and nodal involvement were the most significant adverse prognostic factors. Tumours confined to the gastric wall, node negative cases, middle and distal location, differentiated tumours, female sex and age more than 50 years were associated with relatively good long-term results: overall 5-year survival was 50% or better, overall 10-year survival was 40% or better.

CONCLUSION

The combined treatment showed significant but manageable acute toxicity. The long-term results seem encouraging and support further investigations in multimodal treatment of gastric cancer.

[Intraoperative radiotherapy in the combined treatment of stomach cancer. Methodological and technical aspects]

Theoretical, experimental and clinical rationale is discussed for selection of targets and main parameters of intraoperative radiotherapy for gastric cancer. Topometric and dosage research has been carried out. Original technological equipment has been developed for safe treatment using the domestic accelerator Mikrotron-M. Procedures for continuous relay pre- and intraoperative radiotherapy of gastric tumors in conjunction with radical surgery have been devised and adapted to operation of a specialized clinical facility.

[Results of clinical studies of the efficacy of intraoperative radiotherapy in combined treatment of stomach cancer]

The results of clinical application of an original method of operable gastric cancer treatment including pre- and intraoperative irradiation (IORT) and radical intervention are presented. According to a randomized study, combination treatment did not involve intra- and postoperative complication rates higher than those of surgery alone. Moreover, a significant decrease in postoperative pancreatitis was registered. IORT is a highly effective method of adjuvant treatment of operable gastric cancer. Due to its application in conjunction with preoperative irradiation and radical surgery, the end results of locally-advanced gastric cancer improved.

A prospective, randomized trial of pre-operative and intraoperative radiotherapy versus surgery alone in resectable gastric cancer

INTRODUCTION

Worldwide, gastric cancer remains one of the most common malignancies. Discouraging survival rates after surgical treatment promote the study of adjuvant therapy. A prospectively, randomized, controlled clinical trial was performed in order to determine whether pre-operative and intraoperative radiotherapy improves treatment results of gastrectomy for stomach carcinoma.

METHODS

From 1993 to 1998, 112 patients were randomized and underwent exploratory laparotomy; among them 78 satisfied protocol requirements and entered in the trial. Patients in the experimental group were treated with pre-operative radiotherapy (20 Gy/5 days), gastrectomy and intraoperative radiotherapy (20 Gy using 8-12 electrons). Patients in the control group underwent surgery alone.

RESULTS

Incidence and distribution of post-operative complications were similar in both groups except significantly higher incidence of pancreatitis after surgical treatment. No late radiation-related morbidity was registered. There was no significant difference in survival between the two treatment groups (Chi(2)=1.026, df=1, P=0. 311) as well as in N0 (Chi(2)=0.0029, df=1, P=0.956) and T1-2 subgroups (Chi(2)=0.1928, df=1, P=0.660). In contrast, combined treatment had marked survival advantage in more advanced stages: in the case of lymph-node involvement (Chi(2)=4.19, df=1, P=0.04) and extragastric tumour extension (Chi(2)=4.118, df=1, P=0.042).

CONCLUSION

The proposed intensive treatment programme is feasible, shows good acute and late tolerance and has the potential to improve survival in patients with locally advanced gastric cancer.

A prospective, randomized trial of pre-operative and intraoperative radiotherapy versus surgery alone in resectable gastric cancer

INTRODUCTION

Worldwide, gastric cancer remains one of the most common malignancies. Discouraging survival rates after surgical treatment promote the study of adjuvant therapy. A prospectively, randomized, controlled clinical trial was performed in order to determine whether pre-operative and intraoperative radiotherapy improves treatment results of gastrectomy for stomach carcinoma.

METHODS

From 1993 to 1998, 112 patients were randomized and underwent exploratory laparotomy; among them 78 satisfied protocol requirements and entered in the trial. Patients in the experimental group were treated with pre-operative radiotherapy (20 Gy/5 days), gastrectomy and intraoperative radiotherapy (20 Gy using 8-12 electrons). Patients in the control group underwent surgery alone.

RESULTS

Incidence and distribution of post-operative complications were similar in both groups except significantly higher incidence of pancreatitis after surgical treatment. No late radiation-related morbidity was registered. There was no significant difference in survival between the two treatment groups (Chi(2)=1.026, df=1, P=0. 311) as well as in N0 (Chi(2)=0.0029, df=1, P=0.956) and T1-2 subgroups (Chi(2)=0.1928, df=1, P=0.660). In contrast, combined treatment had marked survival advantage in more advanced stages: in the case of lymph-node involvement (Chi(2)=4.19, df=1, P=0.04) and extragastric tumour extension (Chi(2)=4.118, df=1, P=0.042).

CONCLUSION

The proposed intensive treatment programme is feasible, shows good acute and late tolerance and has the potential to improve survival in patients with locally advanced gastric cancer.

Thermoradiotherapy of patients with locally advanced carcinoma of the rectum

The effectiveness of local hyperthermia was investigated in 56 patients with locally advanced carcinoma of the rectum (T4N0M0). All received combined heat and radiation therapy as a pre-operative treatment. The control group consisted of 59 patients with the same stage of disease as those who were only irradiated. Both groups of patients underwent the same surgical procedure. The total tumour dose of ionizing radiation was 40 Gy in 10 fractions, three times a week. The tumour was heated four or five times to a maximum of 42-43 degrees C by electromagnetic waves with a frequency of 905 MHz before irradiation. Each heating session lasted 60 min. Patients were selected on the principle of randomization: 16.1% of patients (n = 9; n: actual number of patients) showed complete response and 53.6% (n = 30) showed significant regression of the primary tumour compared with 1.7% (n = 1) and 33.9% (n = 20) in the control group, respectively. The differences were significant (p less than 0.05). It was found that thermoradiotherapy allowed the 5-year survival rate of patients to increase up to 35.6% (n = 12) compared with 6.6% (n = 7) in the control group (p less than 0.05).

[The function of the hepatobiliary system in patients with cholelithiasis based on hepatocholescintigraphic data]

Function of the hepatobiliary system in 35 patients with cholelithiasis of mild and average grave types and in 36 examinees after cholecystectomy without complaints and with the post-cholecystectomy syndrome was assessed with dynamic hepatocholescintigraphy which was shown to be an effective method for assessment of the hepatobiliary system in patients with cholelithiasis and after cholecystectomy. In some patients with cholelithiasis a degree of hepatobiliary disorders, including the frequency of dyskinetic disturbances, grows progressively with the severity of pathology (from a mild clinical type to an average grave one) and is most expressed in patients suffering from the postcholecystectomy syndrome.

[Enteral-tube feeding with cozylate of patients with malignant neoplasms in the early postoperative period following surgical interventions on the abdominal organs]

The authors present clinical results of enteral cozylate tube feeding diet in patients with malignant tumors following abdominal surgical interventions. They found a good tolerance to the drug, rapid recovery of gastrointestinal motility, lack of complications due to cozylate application.

[Radiotherapy in the combined treatment of cancer of the rectum]

Analysis of the results of two methods used in the treatment of operable carcinoma of the rectum showed the advantages of the combined method over the purely surgical method: the survival of patients after combined treatment was practically twice that among patients subjected only to operation. No essential differences were found in the character and incidence of postoperative complications and postoperative lethality. All this allows the combined method of treatment to be recommended for wide use in clinical practice.

[Results and prospects of preoperative irradiation of tumors]

An analysis of the results of combined therapy of patients with cancer of different sites has shown a high efficacy of the method. The use of radiation therapy in combination with known surgical ablation methods results in a decrease in the number of local recurrences and distant tumor metastases as well as in an increase in the proportion of operable patients with locally spread tumors. These methods contribute to the prolongation of cancer patients' life.

[Use of local hyperthermia in treating cancer patients]

Basic research in thermobiology made it possible to substantiate the advisability of incorporation of local hyperthermia in schemes of radiotherapy of patients with tumors of different sites. Positive experience of thermoradiotherapy of 301 patients with laryngeal, head and neck, uterine and rectal tumors and osteogenic sarcoma using the Soviet equipment indicated the advisability of wider employment of local hyperthermia in various schemes of radio- and combined therapy.

[Use of metronidazole in the preoperative irradiation of stomach cancer patients]

Altogether 70 patients received combined therapy for stomach cancer. A course of gamma-beam therapy (a summary focal dose of 20 Gy) combined with metronidazole was given at the first stage. Three-five days after the discontinuation of radiation therapy the patients were operated upon. Forty-nine (70%) patients were subjected to radical operation. The area of surgical intervention ranged from subtotal resection of the stomach to combined gastrectomy. Lethality after radical operations was 7.5%. Pronounced and extensive dystrophic changes were found in tumors at microscopic examination of resected specimens.

[ECG changes during radiotherapy of stomach cancer]

Myocardial diffuse dystrophic changes were recorded on the ECG of patients with stomach cancer of different site. After a preoperative course of radiation therapy in the summary focal dose up to 24 Gy these changes were aggravated in 63% of cases: changes in the voltage of the QRS complex waves, amplitudes of P and T waves, S-T intervals and the heart rate were noted. The most pronounced ECG changes developed in patients with tumors in the proximal part of the stomach when radiation exposure of the heart corresponded to 100% of a focal dose. The voltage of the QRS complex waves decreased, the amplitude of P waves increased, a rise of the S-T interval was noted, the amplitude of T waves decreased.

[Statistical analysis of the results of the combined treatment of rectal cancer]

Statistical processing of the results of combined treatment of 131 patients with rectal cancer using factor and regression analysis has shown that the stage and period of disease, tumor growth depth and radiation changes in tumorous tissues produce a considerable effect on the patients' lifetime. The authors found a respective discriminant function that made it possible to single out a group of patients with a high risk of mortality.

[Aspects of the preoperative radiation therapy of patients with rectal and colonic cancer]

The authors present some data on 288 patients with colonic and rectal cancer who were given preoperative radiotherapy, and on 145 patients with rectal cancer who underwent surgery only. In operable rectal cancer intensive irradiation at a single focal dose of 6.5 Gy and summary dose of 19.5 Gy (3 daily fractions), in operable colonic cancer 4 and 20 Gy (5 daily fractions respectively). The five-year survival rate attained during combined treatment of rectal cancer exceeded that after radical operations by 30%. Fractional-extended irradiation at a single focal dose of 4 Gy and summary dose of 40 Gy (every other day) in 44.6% of the patients permitted one to make locally disseminated rectal cancer resectable. Preoperative irradiation of locally disseminated rectal cancer with a preliminary synchronization of the tumor cell division cycle with 5-fluorouracil (a single focal dose of 6 Gy, summary dose of 36 Gy for irradiation twice a week) was well tolerated by the patients, and its effect on tumors was more noticeable as compared to radiotherapy only. Marked radiation reactions were absent in colonic cancer, radical operation (hemicolectomy) entailed no additional difficulties. Local recurrences were not noted in either of 10 patients who had been followed-up in the course of 1 year.