Mutant p53-induced immortalization of primary human mammary epithelial cells

Mutations of the p53 gene are the most frequent genetic lesions in breast cancer, suggesting a critical role for p53 protein in normal mammary cell growth control. Indeed, the p53-targeting human papillomavirus oncogene E6 induces efficient immortalization of normal human mammary epithelial cells (MECs). To assess whether selective loss of p53 is sufficient for MEC immortalization, we introduced seven missense mutants and one single-amino acid deletion mutant (del239) of p53 into the 76N normal MEC strain. Although the missense mutants failed to immortalize MECs, the del239 mutant reproducibly immortalized these cells. The immortal cells were anchorage dependent and nontumorigenic, indicating a preneoplastic transformation. Gamma-irradiation of these cells failed to induce G1 cell cycle arrest and did not lead to an increase in WAF1 and mdm-2 mRNA levels, demonstrating a loss of the endogenous p53 function. These results demonstrate that selective ablation of p53 function by a dominant-negative mutant is sufficient for immortalization of MECs. Availability of an immortalizing as well as several nonimmortalizing p53 mutants should help identify functions critical for cell growth control by p53 in mammary epithelial cells.

Prognostic factors for local and distant recurrence in stage I and II cervical carcinoma

PURPOSE

The effects of tumor size, parametrial involvement, and other variables on treatment outcome for patients with Federation Internationale de Gynecologie et d'Obstetrique (FIGO) Stage I or II cervical carcinoma, as well as treatment complications, were analyzed retrospectively.

METHODS AND MATERIALS

Records of 125 patients with FIGO Stage I or II carcinoma of the uterine cervix selected for curative radiotherapy between January 1980 and December 1990 were reviewed. Twelve patients (9.9%) underwent adjuvant extrafascial hysterectomy and 8 patients (6.4%) received chemotherapy. Median age was 55 years. Median follow-up time was 40 months, and minimum follow-up time was 24 months. The data were analyzed for site of first relapse, survival, overall incidence of complications, and incidence of grade 4 complications.

RESULTS

The overall 5-year survival was: Stage IA: 100%, Stage IB: 72%, Stage IIA: 90%, and Stage IIB: 72%. The 5-year survival with no evidence of disease (NED) was: Stage IA: 100%, Stage IB: 67%, Stage IIA: 90%, and Stage IIB: 50%. Patients with bulky (> 5 cm) tumors had a shorter overall and NED survival than patients with nonbulky tumors (53% vs. 83%; p = 0.0008 and 44% vs. 78%; p = 0.0001, respectively). Thirty-nine tumor recurrences (39 out of 125 = 31%) occurred and were scored as local (23 out of 125 = 18.3%), if initial failure had a local component, or distant (16 out of 125 = 12.7%), if initial failure was distant only. Patients with bulky (more than 5 cm) tumors (32 out of 125) were more likely to experience a recurrence (18 out of 32 = 56%) than patients with nonbulky tumors (21 out of 93 = 22%; p = 0.0004). The initial site of recurrence was more likely to be local for bulky tumors (14 out of 18 = 78%) than for nonbulky tumors (9 out of 21 = 43%; p = 0.03). The probability of a recurrence increased with the number of involved parametria (none: 20 out of 78 = 25%; one: 12 out of 34 = 35%; two: 7 out of 13 = 54%; p = 0.04 for linear trend), as did the probability that the initial failure was distant rather than local (none: 4 out of 20 = 20%; one: 7 out of 12 = 58%; two: 5 out of 7 = 71%; p = 0.01 for linear trend). Positive lymph nodes, vessel invasion, and low hemoglobin level all correlated with an increased risk of a recurrence (RR 2.41, p = 0.004; RR 2.20, p = 0.01; OR 2.02, p = 0.01, respectively). There were 46 complications among 37 (29%) patients. The incidence of grade 4 complications was 8.8% (11 out of 125). History of pelvic surgery and bulky tumor were significant predictors of a grade 4 complication (p < 0.0001 and 0.021, respectively). Also, a dose rate to point A of > 0.6 Gy/h increased the chance of a grade 4 complication (p = 0.007).

CONCLUSION

For patients with FIGO Stage I or II cervical carcinoma, tumor size was more predictive of local recurrence than was overall stage, and the extent of parametrial involvement was strongly predictive of distant recurrence, as was the stage. These findings suggest that tumor size and extent of parametrial involvement should be incorporated into the staging system. Patients with bulky tumors had a shorter survival and were more likely to experience a grade 4 toxicity of therapy. Dose rate to point A of > 0.6 Gy/h was associated with the increased risk of grade 4 complications.

Increased risk of second malignant neoplasms outside radiation fields in patients with cervical carcinoma

BACKGROUND

The relative risk of second primary cancers was evaluated in 125 women with International Federation of Gynecology and Obstetrics (FIGO) Stages I and II cervical carcinoma treated radically with radiation therapy between January 1980 and December 1990.

METHODS

Medical records of patients were reviewed to evaluate the incidence of second malignant neoplasms. Only tumors histologically proven were scored. The annual 5-year age-specific cancer incidence data per 100,000 white women in the years 1981-1985 were obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results database. The relative risks were calculated as the ratio of observed-to-expected numbers of second cancers, using person-years at risk accumulated for each individual in the study.

RESULTS

During the follow-up time (through December 1992), 10 women whose median age was 65.5 years at the time cervical cancer was diagnosed were found to have 11 second primary cancers. Nine of these cancers were metachronous with regard to cervical cancer and included breast (4), lung (2), myeloma (1), non-Hodgkin's lymphoma (1) and vulva(1). The metachronous tumors were diagnosed at a median age of 74 years and at median follow-up time of 34 months. Two of the cancers were synchronous with cervical cancer and included bladder (1) and thyroid (1). All of the second tumors were located outside radiation fields. None of the patients with second tumors received chemotherapy during treatment for cervical carcinoma. The relative risk of developing a second cancer of any type was 2.31 (95% confidence interval [CI] = 1.15-4.13), whereas the relative risk of developing a metachronous breast cancer was 2.64 (95% CI = 0.72-6.75).

CONCLUSIONS

An increased risk of second primary cancers developing was observed among 125 patients with FIGO Stages I and II cervical carcinoma, which may suggest an abnormal genetic background and/or a common etiology for the initial and second tumors. The increased risk of breast cancer occurring as a second primary is in contrast with previously published studies reporting a decreased risk of breast cancer in survivors of cervical cancer.

Boron neutron capture therapy for murine malignant gliomas

Boron neutron capture therapy (BNCT) involves administration of a boron compound followed by neutron irradiation of the target organ. The boron atom captures a neutron, which results in the release of densely ionizing helium and lithium ions that are highly damaging and usually lethal to cells within their combined track length of approximately 12 microns. Prior to Phase I clinical trials for patients with malignant gliomas, mice with glioma 261 intracerebral tumors were fed D,L-3-(p-boronophenyl)alanine and irradiated with total tumor doses of 1000-5000 RBE-cGy of single fraction thermal neutrons to determine the maximum tolerated dose and effect on survival. These mice were compared to mice that received D,L-3-(p-boronophenyl)alanine alone, neutron irradiation alone, photon irradiation alone, or no treatment. Additional normal mice received escalating doses of neutron irradiation to determine its toxicity to normal brain. BNCT caused a dose-dependent, statistically significant prolongation in survival at 1000-5000 RBE-cGy. At 3000 RBE-cGy, median survival rates of the BNCT and untreated control groups were 68 and 22 days, respectively, with a long-term survival rate of 33%. At 4000 RBE-cGy, median survival was 72 and 21 days, respectively, with a long-term survival rate of 43%. At lower radiation doses, the extended survival was comparable between the BNCT and photon-irradiated mice; however, at 3000 and 4000 RBE-cGy the median survival of BNCT-treated mice was significantly greater than photon-irradiated mice. The maximum tolerated single fraction dose to normal brain was approximately 2000 RBE-cGy.

Use of the omental J flap for better delivery of radiotherapy to the pelvis

The surgically created omental J flap (or synthetic equivalents) can facilitate radiation therapy, particularly brachytherapy, in which adhesions of the pelvis would otherwise limit its value. The J flap used in this role has an occasional place in the management of patients with carcinoma and exemplifies how surgical procedures and irradiation can be combined for more effective treatment of carcinomas.

Ultrasound for diagnosing and preventing malplacement of intrauterine tandems

Postoperative B-mode ultrasound was used to evaluate final tandem position in 50 consecutive placements (28 patients). In 34% (17 of 50), the tandem was found to be suboptimally positioned; in 24% (12 of 50), it penetrated the myometrium; and in 10% (five of 50), it frankly perforated the uterus. The uterine fundus was the region most commonly perforated, and the anterior myometrium was the site most frequently penetrated. In all cases in which postoperative ultrasound showed malpositioning, the clinical and radiographic assessment indicated proper intracavitary placement. Ultrasound affected clinical management in 42% (21 of 50) of the placements involving 61% (17 of 28) of the patients. To improve tandem placement, we used intraoperative real-time ultrasound to guide 73 consecutive surgical insertions. Ultrasound clearly visualized the procedure, allowing tandems to be positioned with confidence even in the most difficult cases. The immediate feedback from intraoperative ultrasound eliminated malplacements and thus the need for a second anesthesia to reposition the tandem.

Clinical considerations for neutron capture therapy of brain tumors

The radiotherapeutic management of primary brain tumors and metastatic melanoma in brain has had disappointing clinical results for many years. Although neutron capture therapy was tried in the United States in the 1950s and 1960s, the results were not as hoped. However, with the newly developed capability to measure boron concentrations in blood and tissue both quickly and accurately, and with the advent of epithermal neutron beams obviating the need for scalp and skull reflection, it should now be possible to mount such a clinical trial of NCT again and avoid serious complications. As a prerequisite, it will be important to demonstrate the differential uptake of boron compound in brain tumor as compared with normal brain and its blood supply. If this can be done, then a trial of boron neutron capture therapy for brain tumors should be feasible. Because boronated phenylalanine has been demonstrated to be preferentially taken up by melanoma cells through the biosynthetic pathway for melanin, there is special interest in a trial of boron neutron capture therapy for metastatic melanoma in brain. Again, the use of an epithermal beam would make this a practical possibility. However, because any epithermal (or thermal) beam must contain a certain contaminating level of gamma rays, and because even a pure neutron beam causes gamma rays to be generated when it interacts with tissue, we think that it is essential to deliver treatments with an epithermal beam for boron neutron capture therapy in fractions in order to minimize the late-effects of low-LET gamma rays in the normal tissue. I look forward to the remainder of this Workshop, which will detail recent progress in the development of epithermal, as well as thermal, beams and new methods for tracking and measuring the uptake of boron in normal and tumor tissues.

Monte Carlo based dosimetry and treatment planning for neutron capture therapy of brain tumors

Monte Carlo based dosimetry and computer-aided treatment planning for neutron capture therapy have been developed to provide the necessary link between physical dosimetric measurements performed on the MITR-II epithermal-neutron beams and the need of the radiation oncologist to synthesize large amounts of dosimetric data into a clinically meaningful treatment plan for each individual patient. Monte Carlo simulation has been employed to characterize the spatial dose distributions within a skull/brain model irradiated by an epithermal-neutron beam designed for neutron capture therapy applications. The geometry and elemental composition employed for the mathematical skull/brain model and the neutron and photon fluence-to-dose conversion formalism are presented. A treatment planning program, NCTPLAN, developed specifically for neutron capture therapy, is described. Examples are presented illustrating both one and two-dimensional dose distributions obtainable within the brain with an experimental epithermal-neutron beam, together with beam quality and treatment plan efficacy criteria which have been formulated for neutron capture therapy. The incorporation of three-dimensional computed tomographic image data into the treatment planning procedure is illustrated. The experimental epithermal-neutron beam has a maximum usable circular diameter of 20 cm, and with 30 ppm of B-10 in tumor and 3 ppm of B-10 in blood, it produces (with RBE weighting) a beam-axis advantage depth of 7.4 cm, a beam-axis advantage ratio of 1.83, a global advantage ratio of 1.70, and an advantage depth RBE-dose rate to tumor of 20.6 RBE-cGy/min (cJ/kg-min). These characteristics make this beam well suited for clinical applications, enabling an RBE-dose of 2,000 RBE-cGy/min (cJ/kg-min) to be delivered to tumor at brain midline in six fractions with a treatment time of approximately 16 minutes per fraction. With parallel-opposed lateral irradiation, the planar advantage depth contour for this beam (with the B-10 distribution defined above) encompasses nearly the whole brain. Experimental calibration techniques for the conversion of normalized to absolute treatment plans are described.

Response to total body irradiation in dermatomyositis

There were two patients with severe dermatomyositis refractory to immunosuppressive therapy treated with 150 rad of total body irradiation given over a period of 5 weeks. Both patients responded promptly with minimal side-effects and remain in partial remission 42 and 18 months after completion of the treatment. Total body irradiation is effective in some patients with dermatomyositis who are refractory to standard therapy.

Splenic irradiation in the treatment of patients with chronic myelogenous leukemia or myelofibrosis with myeloid metaplasia. Results of daily and intermittent fractionation with and without concomitant hydroxyurea

Seventeen patients with either chronic myelogenous leukemia (CML) or myelofibrosis with myeloid metaplasia (MMM) received 24 courses of splenic irradiation at this institution from 1973 to 1982. Eleven of the 17 patients had received prior chemotherapy. Patients were treated with 60Co gamma rays or 6 MV photons. The fraction size ranged from 15 to 100 rad and the total dose per treatment course from 15 to 650 rad, with the exception of one patient who received 1650 rad. Fourteen of 19 courses (71%) given for splenic pain yielded significant subjective relief while 17 of 26 courses given for splenomegaly obtained at least 50% regression of splenic size. Blood counts were carefully monitored before each treatment to limit hematologic toxicity. From this experience, the authors conclude that splenic irradiation effectively palliates splenic pain and reverses splenomegaly in the majority of patients with CML and MMM. Intermittent fractionation (twice or thrice weekly) is more convenient for the patient, appears to be as effective as daily treatment, and may be associated with less hematologic toxicity. Preliminary results of concurrent treatment with splenic irradiation and oral hydroxyurea show promise and warrant further study.

Total body irradiation not effective in inclusion body myositis

Four patients with inclusion body myositis were treated with 150 rad of total body irradiation given in 5 weeks. One patient responded subjectively and transiently, but no patient showed clear benefit. This treatment is not recommended for inclusion body myositis.

Intraoperative real-time ultrasonography during intrauterine tandem placement

Real-time ultrasound is used in the operating room as an aid in the placement of the intrauterine tandem. This method provides excellent imaging of the ongoing procedure, facilitating final tandem placement in the endometrial cavity even in the most difficult case.

Malignant transformation of vaginal endometriosis

A well-documented case of extraovarian endometriosis undergoing malignant transformation is presented. A vaginal focus of endometriosis was biopsied over a 13-year interval during which time progression from benign to malignant disease was observed. Exogenous estrogen replacement was administered throughout the interval of transformation. The pathology, pertinent literature, and implications of the present case are discussed.

Combined effect of diethyldithiocarbamate (DDC) and modest hyperthermia on Chinese hamster (V79) cell survival and DNA strand break repair following photon irradiation

Previous studies from our institution have shown that 10(-4) M DDC enhances the effects of radiation and of hyperthermia treatment at 43 degrees C on the killing of Chinese hamster (DON) cells. We herein report studies on the combined effect seen at more modest temperatures (41 degrees C) which can be achieved in humans by whole body heating without the need for general anesthesia. Treatment of V79 cells with DDC for 60 minutes at 37 degrees C or 41 degrees C had minimal toxicity at concentrations up to 5 X 10(-5) M. When cells were irradiated with single doses up to 1000 rad (137Cs, 350 rad/min), pre-incubation with 10(-4) M DDC had no effect on cell survival at 37 degrees C, but markedly decreased survival at 41 degrees C (D37 = 475 rad without DDC, 270 rad with DDC). The mechanism of this increased cell killing is not known. We observed, however, that there is no repair of DNA single strand breaks in DNA from irradiated V79 cells previously held at 41 degrees C in the presence of 10(-4) M DDC. Without DDC, repair of SSB was similar at 37 degrees C and 41 degrees C.

Radiation therapy alone in the treatment of carcinoma of the uterine cervix. II. Analysis of complications

A retrospective analysis was carried out on 811 patients with histologically proven invasive carcinoma of the uterine cervix treated with irradiation alone. A correlation was made of the doses of irradiation delivered to the pelvic organs with external beam and intracavitary insertions. Approximately 3% of the patients exhibited grade 2 gastrointestinal complications, and 2% developed grade 2 urinary complications; 5% of the patients developed grade 3 gastrointestinal complications, and 3% developed grade 3 urinary complications. Other types of complications, primarily grade 2, such as vaginal necrosis, pelvic abscess, thrombophlebitis, etc, were seen in approximately 5% of the patients. Thus, the total percentage of patients developing grade 2 complications was 10% and grade 3 complications, approximately 8%. About 25% of the patients who had complications showed more than one sequela. The most frequently observed grade 2 complications were proctitis, cystitis, vaginal stenosis, and partial small bowel obstruction which were treated with conservative management. Grade 3 complications required surgical treatment and consisted most frequently of ureteral stricture, vesicovaginal fistula, rectovaginal fistula, sigmoid stricture, small bowel obstruction, proctitis, and large rectal ulcers. The most significant factor affecting the appearance of complications was the total dose of irradiation delivered to the pelvic organs by the whole pelvis external irradiation and intracavitary insertions. With maximum total doses up to 8000 rad the incidence of grade 2 and 3 complications was less than 5%. However, with higher doses the incidence of complications increased to 10% to 15%. In patients receiving total doses of 6000 rad to the bladder or rectum, more complications were noted when only one intracavitary insertion was performed, as compared with two or three. Eighty percent of the rectosigmoid complications occurred within 30 months of initial therapy, in contrast to 48 months for the urinary complications. Patients who developed complications had survival rates comparable to those without complications. This underscores the need to rapidly institute treatment on patients who have severe injury after radiation therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrasound used for assessing the in situ position of intrauterine tandems

Intracavitary radiation is an integral part of the treatment in many gynecologic cancers. The intrauterine tandem has a well-established role in treating both cervical and endometrial malignancies. The effectiveness of this therapy and its complications are directly related to the proper intracavitary position of the tandem. To date, there has been no objective technique appropriate for routine use in assessing the precise in situ location of these devices, apart from plain abdominal films. As such, little is known about the incidence or types of procedural complications and the sequelae associated with improper tandem placement. Here it is reported that ultrasound is an effective tool for evaluating the in situ position of the intrauterine tandem. Two cases are presented demonstrating important applications of this method.

Radiation therapy alone in the treatment of carcinoma of uterine cervix. I. Analysis of tumor recurrence

This is a retrospective analysis with emphasis on the patterns of failure in 849 patients with histologically proven invasive carcinoma of the uterine cervix treated with irradiation alone. In 281 patients with Stage IB tumors, the total incidence of pelvic failure was 6.4% (two without and 16 combined with distant metastasis). In 88 patients with Stage IIA, 12.5% failed in the pelvis (one without and ten combined with distant metastasis). The total pelvic failure rate in Stage IIB was 17.4% (22 without and 22 combined with distant metastasis). In 212 patients with Stage III, the overall pelvic failure rate was 35.8% (31 without and 45 combined with distant metastasis). Approximately 25% of the pelvic recurrences were central (cervix or vagina) and 75% parametrial. The overall incidence of distant metastasis was 13.5% for Stage IB, 27.3% for Stage IIA, 23.8% for Stage IIB, and 39.6% in Stage III. Higher doses of irradiation delivered to the medial and lateral parametrium with external beam irradiation and intracavitary insertions were correlated with a lower incidence of parametrial failures in all stages, except IB. In Stage IIA, medial parametrial doses below 9000 rad resulted in 10/78 = 12.8% pelvic failures, in contrast to one recurrence in 10 patients treated with doses over 9000 rad. In Stage IIB, doses below 9000 rad yielded a pelvic recurrence rate of 36/203 (17.7%) compared to 5/49 (10.2%) with higher doses. In Stage III there were 66/167 (39.5%) recurrences with doses below 9000 rad and 10/44 (22.7%) with larger doses. Statistically significant differences were observed among the Stage IIB (P = 0.02) and III patients (P = 0.005) respectively. The lateral parametrial dose also showed some correlation with tumor control, although the differences were not statistically significant. The survival in patients with Stage IIB and III was 10% higher in the patients treated with higher parametrial doses. However, the differences are not statistically significant. These results strongly suggest that higher doses of irradiation must be delivered to patients with Stage IIB and III, but improvement in tumor control must be weighed against an increasing number of complications. Factors other than the total doses of irradiation, such as the characteristics of the tumor and the quality of the intracavitary insertion influence the therapeutic results in irradiation of carcinoma of the uterine cervix. Other therapeutic approaches must be designed to improve the effect of irradiation in the tumor without further injury to the normal tissues. Hypoxic cell sensitizers, hyperthermia and high LET particles are under investigation.

Effect of bladder distension on dosimetry in gynecological implants

In order to quantitate the impact of bladder distension on implant position and on radiation dosage to various parts of the bladder, 24 patients with gynecological neoplasms underwent computed tomographic scanning of the pelvis following insertion of afterloading intracavitary applicators. Shifting of the applicators due to bladder distension was measured at and two inches above the level of the vaginal ovoids. By maintaining a residual vesical volume of 200-300 ml with contrast material, radiation exposure to a large part of the bladder was reduced significantly while only a minor displacement of the implant system was noted.

New assessment of the prognostic significance of histopathology in Hodgkin's disease for laparotomy-negative stage I and stage II patients

This paper describes preliminary radiotherapy results in 90 patients with Stage I and II Hodgkin's disease who were evaluated by laparotomy, including splenectomy, and liver and bone marrow biopsies. As a result of selection by laparotomy, the estimated five-year survival rate for these patients was 96%. No statistically significant differences were detected in the disease-free survival for patients with mixed cellularity, nodular sclerosis, and lymphocytic predominance disease. Since only one patient with lymphocytic depletion was in this series, no statement can be made regarding this rare histopathology. Patterns of new disease differed for Stage I and II patients. The major difference was that patients with nodular sclerosing Stage II presentations involving the mediastinum were at considerable risk of developing subsequent disease in the pulmonary parenchyma or the pleura. This finding, together with the demonstration that a histologic diagnosis of mixed cellularity did not carry an inferior prognosis, indicates the need for reassessment of the appropriateness of applying treatment programs based on results of lymphangiographically staged patients to Stage I and II patients evaluated by laparotomy.

Age response to x-radiation of murine lymphoma cells synchronized in vivo

Cells of a transplantable murine lymphoma line were partially synchronized in vivo by administration of a single dose of 0.5 mg of hydroxyurea per lymphoma-bearing mouse. At various times after administration of hydroxyurea, the femurs of the lymphomatous mice were X-irradiated, and the number of lymphoma colony-forming units per femur were then assayed by the spleencolony technique. A well-defined age response to irradiation of the lymphoma cells in vivo, similar to that of HeLa cells in vitro, was observed.