Emergence of increased cerebral metastasis after high-dose preoperative radiotherapy with chemotherapy in patients with locally advanced nonsmall cell lung carcinoma.

BACKGROUND: In recent years, combined modality induction therapy has defined a new standard of care in the treatment of patients with American Joint Committee on Cancer (AJCC) Stage III nonsmall cell lung carcinoma, providing improved local control and improved disease-free survival. However, the majority of Stage III patients still die of recurrent disease. METHODS: Forty-two consecutive patients with AJCC Stage IIIA/IIIB nonsmall cell lung carcinoma (NSCLC) who were undergoing induction chemoradiotherapy followed by surgical resection of the primary NSCLC tumor between December 1, 1987 and September 1, 1999 were analyzed for resectability, survival, and patterns of disease failure. These patients received cisplatin (60 mg/m(2)) on Days 1 and 22 and etoposide (100 mg/m(2)) on Days 1, 2, and 3, and Days 22, 23, and 24 together with 5940 centigrays (cGy) of radiation in 180-cGy fractions delivered over 6 weeks. RESULTS: Thirty-one of the 42 patients (74%) underwent surgical resection of the primary lung tumor and mediastinal lymph nodes after chemoradiotherapy. No surgical deaths were reported. The median survival of these 31 patients was 52 months. The 5-year survival estimate using the Kaplan-Meier method was 49.9%. The local control rate was 80%. The incidence of distant metastases other than in the brain was reduced. The most frequently involved site of isolated first recurrence was the brain. The median time to brain recurrence was 7.5 months from the time of surgical resection. All brain metastases were detected within 2 years. CONCLUSIONS: The high incidence of isolated brain metastasis after induction chemoradiotherapy and curative resection and their response to treatment suggest that routine scans of the brain may be indicated in the follow-up of patients with locally advanced NSCLC.

Clinically evident fat necrosis in women treated with high-dose-rate brachytherapy alone for early-stage breast cancer.

PURPOSE: To investigate the incidence of and variables associated with clinically evident fat necrosis in women treated on a protocol of high-dose-rate (HDR) brachytherapy alone without external-beam whole-breast irradiation for early-stage breast carcinoma. METHODS AND MATERIALS: From 6/1997 until 8/1999, 30 women diagnosed with Stage I or II breast carcinoma underwent surgical excision and postoperative irradiation via HDR brachytherapy implant as part of a multi-institutional clinical Phase I/II protocol. Patients eligible included those with T1, T2, N0, N1 (< or = 3 nodes positive), M0 tumors of nonlobular histology with negative surgical margins, no extracapsular lymph-node extension, and a negative postexcision mammogram. Brachytherapy catheters were placed at the initial excision, re-excision, or at the time of axillary sampling. Direct visualization, surgical clips, ultrasound, or CT scans assisted in delineating the target volume defined as the excision cavity plus 2-cm margin. High activity (192)Ir (3-10 Ci) was used to deliver 340 cGy per fraction, 2 fractions per day, for 5 consecutive days to a total dose of 34 Gy to the target volume. Source position and dwell times were calculated using standard volume optimization techniques. Dosimetric analyses were performed with three-dimensional postimplant dose and volume reconstructions. The median follow-up of all patients was 24 months (range, 12-36 months). RESULTS: Eight patients (crude incidence of 27%) developed clinically evident fat necrosis postimplant in the treated breast. Fat necrosis was determined by clinical presentation including pain and swelling in the treated volume, computed tomography, and/or biopsy. All symptomatic patients (7 of 8 cases) were successfully treated with 3 to 12 months of conservative management. Continuous variables that were found to be associated significantly with fat necrosis included the number of source dwell positions (p = 0.04), and the volume of tissue which received fractional doses of 340 cGy, 510 cGy, and 680 cGy (p = 0.03, p = 0.01, and p = 0.01, respectively). Other continuous variables including patient age, total excised tissue volume, tumor size, number of catheters, number of days the catheters were in place, planar separation, dose homogeneity index (DHI), and uniformity index (UI) were not significant. Discrete variables including the presence/absence of DCIS, sentinel versus full axillary nodal assessment, receptor status, presence/absence of diabetes, and the use of chemotherapy or hormone therapy were not found to have a significant association with the risk of fat necrosis. CONCLUSIONS: In this study of HDR brachytherapy of the breast tumor excision cavity plus margin, treatment was planned and delivered in accordance with the dosimetric parameters of the protocol resulting in a high degree of target volume dose homogeneity. Nonetheless, at a median follow-up of 24 months, a high rate of clinically definable fat necrosis occurred. The overall implant volume as reflected in the number of source dwell positions and the volume of breast tissue receiving fractional doses of 340, 510, and 680 cGy were significantly associated with fat necrosis. Future dosimetric optimization algorithms for HDR breast brachytherapy will need to include these factors to minimize the risk of fat necrosis.

Paclitaxel and concurrent radiation for locally advanced pancreatic cancer.

PURPOSE: To determine the activity and toxicity of paclitaxel and concurrent radiation for pancreatic cancer. METHODS AND MATERIALS: Forty-four patients with locally unresectable pancreatic cancer were studied. Patients received paclitaxel, 50 mg/m(2) by 3 h i.v. (IV) infusion, weekly, on Days 1, 8, 15, 22 and 29. Radiation was administered concurrently to a total dose of 50.4 Gy, in 1.80 Gy fractions, for 28 treatments. RESULTS: Nausea and vomiting were the most common toxicities, Grade 3 in five patients (12%). Two patients (5%) had Grade 4 hypersensitivity reactions to their first dose of paclitaxel. Of 42 evaluable patients, the overall response rate was 26%. The median survival was 8 months, and the 1-year survival was 30%. CONCLUSION: Concurrent paclitaxel and radiation demonstrate local-regional activity in pancreatic cancer. Future investigations combining paclitaxel with other local-regional and systemic treatments are warranted.

Margin width as a determinant of local control with and without radiation therapy for ductal carcinoma in situ (DCIS) of the breast.

In order to assess the utility of margin width in relation to other histopathologic features as a determinant of local control in ductal carcinoma in situ (DCIS) of the breast, we retrospectively examined the treatment of 109 breasts treated with (n = 54) or without adjuvant radiotherapy (n = 55). Median follow-up was 49 and 54 months for patients treated with excision alone (E) or excision plus adjuvant radiotherapy (E+XRT), respectively. Cases treated with E+XRT were significantly larger and had a trend towards closer surgical margins than those treated with E alone. For all cases, margin width < or = 1 mm and lesion diameter >15 mm were significantly associated with increased local recurrence. Lesion size < or = 15 mm was associated with no cases of local failure regardless of treatment arm. For lesions >15 mm in diameter, there was a significant decrease in 5-year local failure with E+XRT compared to E alone (21% vs. 36%, P = 0.03). Tumor margin >1 mm was associated with a low rate of 5-year local failure for either E alone or E+XRT (10.9% vs. 4.6%, P = NS). Tumor margin < = 1 mm had a high rate of local failure that was not significantly decreased by the addition of adjuvant radiotherapy. These results show that large diameter (>15 mm) and close surgical margins (< or = 1 mm) are the dominant risk factors for local recurrence in DCIS. E+XRT significantly decreased local failure risk compared to E alone for large lesions but not for those with close margins.

High dose radiation therapy and chemotherapy as induction treatment for stage III nonsmall cell lung carcinoma.

BACKGROUND: The current study was conducted to review the authors' experience in treating consecutive patients with American Joint Committee on Cancer (1997 revision) Stage III nonsmall cell lung carcinoma with aggressive preoperative chemoradiation followed by surgical resection. METHODS: The records of all patients who received preoperative chemoradiation were evaluated. Patients received 2 cycles of concurrent cisplatin and etoposide with 5940 centigrays of radiation therapy. They then were reevaluated to determine whether they were surgical candidates. If so, resection of the primary tumor with mediastinal lymph node dissection was performed 4-6 weeks after the completion of preoperative treatment. After adequate healing, an additional four cycles of cisplatin/etoposide or carboplatin/paclitaxel was given. RESULTS: Forty-two patients received preoperative chemoradiation, 33 of whom underwent surgical resection (79%), including 9 patients who underwent pneumonectomies. Complete pathologic responses were observed in 27% of these patients. Postoperative complications were noted in 21% of the patients and included persistent air leak, supraventricular arrhythmia, and empyema. There were no reported treatment-related deaths. The median follow-up was 26 months. The overall 5-year survival rate for all patients was 36.5% and was 45. 3% for patients who underwent resection. A trend toward increased 5-year survival was observed in patients who had a complete pathologic response (57.1%). Univariate analysis revealed the N stage classification to be significant for predicting a complete response. Patterns of failure revealed the brain to be the most common site of first recurrence (50%) and the only site of recurrence in 36% of patients. There was only one case of local failure. CONCLUSIONS: Preoperative chemoradiation using high radiation doses is feasible with acceptable toxicity. The results of the current study suggest an increased complete pathologic response rate and increased overall survival rate compared with reports in the published literature.

Three-dimensional conformal radiotherapy for early stage prostatic cancer: techniques, outcomes, and possible pitfalls.

Advances in radiation therapy have led to the development of multiple methods to deliver radiotherapy accurately to a defined three-dimensional target. This technology is most appropriate in the management of early stage prostatic cancer. Precise delivery of radiotherapy can control prostate cancer while minimizing normal tissue (e.g., bladder and rectum) complications.

Paclitaxel and concurrent radiation for gastric cancer.

PURPOSE: To determine the activity and toxicity of paclitaxel and concurrent radiation for gastric cancer. METHODS AND MATERIALS: Twenty-seven patients were studied. Twenty-five had proximal gastric cancers, two had distal cancers. Eight had esophageal extension, 6 had celiac adenopathy, and 7 had retroperitoneal adenopathy. Patients received paclitaxel, 50 mg/m(2) by 3-hour intravenous (IV) infusion, weekly, on days 1, 8, 15, 22, and 29. Radiation was administered concurrently to a total dose of 45.0 Gy, in 1.80 Gy fractions, for 25 treatments. Patients who were medically or surgically inoperable received a sixth week of paclitaxel with a radiation boost to 50.4 Gy. RESULTS: Esophagitis and gastritis were the most important toxicities, Grade 3 in four patients (15%), and Grade 4 in three patients (11%). Five patients (19%) had Grade 3 nausea. The overall response rate was 56%, including three patients (11%) with a complete response. The 2-year progression-free and overall survival rates were 29% and 31%, respectively. CONCLUSION: Concurrent paclitaxel and radiation demonstrates substantial local-regional activity in gastric cancer. Future investigations combining paclitaxel and radiation with other local-regional and systemic treatments are warranted.

Optimal radiotherapy for prostate cancer: predictions for conventional external beam, IMRT, and brachytherapy from radiobiologic models.

PURPOSE: To determine, on the basis of radiobiological models, optimal modalities of radiotherapy for localized prostate cancer, and to provide a rational basis for therapeutic decisions. METHODS AND MATERIALS: An algorithm based on extensions to the linear-quadratic (LQ) cell survival model is constructed for fractionated and protracted irradiation. These radiobiological models include prostate tumor cell line-derived LQ parameters, clonogen repopulation, repair of sublethal damage, hypoxia, and radioisotope decay. In addition, dose inhomogeneities for both IMRT and brachytherapy (125I and 103Pd) from patient-derived Dose Volume Histograms (DVH), as well as dose escalation, are incorporated. Three risk groups are defined in terms of sets of biologic parameters tailored to correspond to clinical risk groups as follows: Favorable-iPSA <10 and bGS < or =6 and stage T2; Intermediate-one parameter increased; and Unfavorable-two or more parameters increased. Tumor control probabilities (TCP) are predicted for conventional external beam radiotherapy (EBRT, including 3D-CRT), intensity modulated radiotherapy (IMRT), and permanent brachytherapy. RESULTS: Brachytherapy is less susceptible to variations in alpha/beta than EBRT and more susceptible to variations in clonogen potential doubling time (Tp). Our models predict TCP consistent with the bNED results from recent dose escalation trials and long-term outcomes from brachytherapy. TCP from IMRT are systematically superior to those from conventional fractionated RT, and suggests its possible use in dose escalation without additional dose to surrounding normal tissues. For potentially rapidly dividing tumors (Tp < 30 days) 103Pd yields superior cell kill compared with 125I, but for very slowly proliferating tumors the converse is suggested. Brachytherapy predicts equivalent or superior TCP to dose escalated EBRT. For unfavorable risk tumors, combined 45 Gy EBRT+brachytherapy boost predicts superior TCP than with either modality alone. CONCLUSIONS: The radiobiological models presented suggest a rational basis for choosing among several radiotherapeutic modalities based on biologic risk factors. In addition, they suggest that IMRT may potentially be superior to 3D-CRT in allowing dose escalation without increased morbidity, and that brachytherapy, as monotherapy or as boost, may achieve superior tumor control compared with dose escalation 3D-CRT. The latter conclusion is supported by clinical data.

The influence of age and extensive intraductal component histology upon breast lumpectomy margin assessment as a predictor of residual tumor.

PURPOSE: Young age and extensive intraductal component (EIC) histology have been shown to be associated with increased local recurrence in women treated with breast conservation therapy. This study was conducted to determine if the status of the lumpectomy specimen margin consistently predicted for residual tumor burden risk irrespective of these variables. METHODS AND MATERIALS: As part of an institutional prospective approach for breast conservation therapy (BCT), 265 cases with AJCC Stage I/II carcinoma with an initial excision margin that was < or =2 mm or indeterminate were subjected to reexcision. The probability of residual tumor (+RE) was evaluated with respect to tumor size, histopathologic subtype (invasive ductal carcinoma, invasive ductal carcinoma with an EIC, and invasive lobular carcinoma), relative closeness of the measured margin, and the extent of margin positivity graded as focal, minimal, moderate, or extensive. The amount of residual tumor was graded as microscopic, small, medium, or large. All variables were analyzed for patient age < or =45 or >45 years. RESULTS: There was no significant difference in the incidence of a +RE according to age < or =45 versus >45 years when the margin was >0 < or =2 mm. Of the patients aged < or =45 years, the incidence of a +RE with a margin that was positive as compared to >0 < or =2 mm was 71% vs. 23%, respectively (p = 0.002). For women >45 years old, the difference in the incidence of +RE comparing margins that were positive or >0 < or =2 mm was not significant at 50% vs. 40%, respectively (p = 0.23). For all cases in aggregate, age < or =45 years was associated with a greater incidence of +RE as compared to patients aged >45 years with the discrepant incidence of a +RE by age strata most pronounced for focally positive margins (60% vs. 18%;p< or =0.05). In a logistic regression analysis, age (per year, as a continuous variable) and an EIC histology were significantly associated with the probability of a +RE (odds ratio [OR] = 0.80, p = 0.05 and OR = 1.9, p = 0.01, respectively). Tumor size was not significant (p = 0.23). In patients with an EIC histology, margin status is generally less predictive for differences in the incidence of a +RE. Further, the overall magnitude of difference in the incidence of a +RE related to age appears to be minimized when an EIC histology is present. In contrast, for cases classified as having non-EIC histology, there is a near-linear relationship for both age strata with respect to margin status and the incidence of a +RE. When histology is classified as non-EIC, age < or =45 years is consistently associated with a greater risk of residual tumor for all margin status categories. When the extent of margin positivity was graded as focal or minimal, residual tumor was semiquantitatively estimated as a medium/large amount in 33% versus 26% of cases aged < or =45 or >45 years, respectively (p = 0.62). CONCLUSION: For positive lumpectomy specimen margins, younger age is associated with an increased residual tumor risk. An EIC histology appears to be associated with an elevated risk of residual tumor irrespective of age and may undermine the predictive utility of margin status. Therefore, age and an EIC histology should be factored into risk assessments for residual tumor that rely upon margin assessment.

A non-invasive immobilization system and related quality assurance for dynamic intensity modulated radiation therapy of intracranial and head and neck disease.

PURPOSE: To develop and implement a non-invasive immobilization system guided by a dedicated quality assurance (QA) program for dynamic intensity-modulated radiotherapy (IMRT) of intracranial and head and neck disease, with IMRT delivered using the NOMOS Corporation's Peacock System and MIMiC collimator. METHODS AND MATERIALS: Thermoplastic face masks are combined with cradle-shaped polyurethane foaming agents and a dedicated quality assurance program to create a customized headholder system (CHS). Plastic shrinkage was studied to understand its effect on immobilization. Fiducial points for computerized tomography (CT) are obtained by placing multiple dabs of barium paste on mask surfaces at intersections of laser projections used for patient positioning. Fiducial lines are drawn on the cradle along laser projections aligned with nasal surfaces. Lateral CT topograms are annotated with a crosshair indicating the origin of the treatment planning and delivery coordinate system, and with lines delineating the projections of superior-inferior field borders of the linear accelerator's secondary collimators, or with those of the fully open MIMiC. Port films exposed with and without the MIMIC are compared to annotated topograms to measure positional variance (PV) in superior-inferior (SI), right-left (RL), and anterior posterior (AP) directions. MIMiC vane patterns superposed on port films are applied to verify planned patterns. A 12-patient study of PV was performed by analyzing positions of 10 anatomic points on repeat CT topograms, plotting histograms of PV, and determining average PV. RESULTS AND DISCUSSION: A 1.5+/-0.3 mm SD shrinkage per 70 cm of thermoplastic was observed over 24 h. Average PV of 1.0+/-0.8, 1.2+/-1.1, and 1.3+/-0.8 mm were measured in SI, AP, and RL directions, respectively. Lateral port films exposed with and without the MIMiC showed PV of 0.2+/-1.3 and 0.8+/-2.2 mm in AP and SI directions. Vane patterns superimposed on port films consistently verified the planned patterns. CONCLUSION: The CHS provided adequately reproducible immobilization for dynamic IMRT, and may be applicable to decrease PV for other cranial and head and neck external beam radiation therapy.

Dosimetric verification of the dynamic intensity-modulated radiation therapy of 92 patients.

PURPOSE: To verify that optimized dose distributions provided by an intensity-modulated radiation therapy (IMRT) system are delivered accurately to human patients. METHODS AND MATERIALS: Anthropomorphic phantoms are used to measure IMRT doses. Four types of verification are developed for: I) system commissioning with beams optimized to irradiate simulated targets in phantoms, II) plans with patient-optimized beams directed to phantoms simulating the patient, III) patient-phantom hybrid plans with patient-optimized beams calculated in phantom without further optimization, and IV) in vivo measurements. Phantoms containing dosimeters are irradiated with patient-optimized beams. Films are scanned and data were analyzed with software. Percent difference between verified and planned maximum target doses is defined as "dose discrepancy" (deltavp). The frequency distribution of type II deltavp from 204 verification films of 92 IMRT patients is fit to a Gaussian. Measurements made in vivo yield discrepancies specified as deltaivp, also fit to a Gaussian. RESULTS AND DISCUSSION: Verification methods revealed three systematic errors in plans that were corrected prior to treatment. Values of [deltavp] for verification type I are <2%. Type II verification discrepancies are characterized by a Gaussian fit with a peak 0.2% from the centroid, and 158 [deltavp] <5%. The 46 values of [deltavp] >5% arise from differences between phantom and patient geometry, and from simulation, calculation, and other errors. Values of [deltavp] for verification III are less than half of the values of [deltavp] for verification II. A Gaussian fit of deltaivp from verification IV shows more discrepancy than the fit of deltavp, attributed to dose gradients in detectors, and exacerbated by immobilization uncertainty. CONCLUSIONS: Dosimetric verification is a critical step in the quality assurance (QA) of IMRT. Hybrid Verification III is suggested as a preliminary quality standard for IMRT.

Breast conservation in elderly women for clinically negative axillary lymph nodes without axillary dissection.

BACKGROUND: A prospective study was initiated to explore an approach of limited therapy in elderly patients with early clinical stage breast cancer. METHODS: Between 1982 and 1989, 73 women with American Joint Committee on Cancer Stage I/II, clinically negative axillary lymph nodes aged 65 years or older (median age, 74 years) were enrolled in a treatment program consisting of tumor excision, breast and regional lymph node irradiation, and, in 66 patients, tamoxifen. Patients were assessed for disease outcome and complications. RESULTS: At a median follow-up of 54 months, 8-year rates of local and regional lymph node control were 92.5% and 100%, respectively. Eight-year probabilities of disease free, overall, and breast cancer specific survival were 84%, 52.5%, and 93.8%, respectively. There was minimal morbidity associated with either regional irradiation or tamoxifen. CONCLUSIONS: An approach to early breast cancer in the elderly that seeks to limit the aggressiveness of local and systemic therapies appears to result in a satisfactory disease outcome with few complications.

Breast conservation therapy for early stage breast carcinoma with outstanding 10-year locoregional control rates: a case for aggressive therapy to the tumor bearing quadrant.

PURPOSE: Between 1982 and 1988 233 American Joint Committee on Cancer Stage I and II invasive breast carcinomas were prospectively treated in 225 women with conservative tumor excision, careful assessment of histopathological margins, and dose-adjusted irradiation to maximum doses of 70 Gy to the tumor bearing quadrant of the breast. METHODS AND MATERIALS: The pathological stages at presentation were T1N0 and T1N1 in 57% and 13% and T2N0 and T2N1 in 19% and 10% of the patients, respectively. All patients were irradiated according to a policy that, beyond the 50 Gy to the whole breast and draining lymphatics, the tumor-bearing quadrant was boosted in adjustment to the histopathological margin. Normal tissue margins of < 2 mm were considered positive, margins 2-5 mm close, and margins > 5 mm negative and were boosted with 20, 15, and 10 Gy, respectively. Patients in whom the margin could not be assessed were re-excised or boosted to 20 Gy. Re-excisions with no residual carcinoma were not boosted. Most patients boosted to 20 Gy to the tumor-bearing quadrant received interstitial 192-Ir implantations. RESULTS: The actuarial local control rates in the treated breast were 97.5% at 10 years with three recurrences having occurred at a median of 4.5 years after completion of radiotherapy. An additional two patients failed regionally outside the irradiation portals. The overall and disease-free survival of the whole group is 87.5% and 77%, respectively. CONCLUSION: The approach to breast conservation therapy followed in this study has resulted in outstanding local control rates and suggests that there may be a subset of patients that could be irradiated to the tumor bearing quadrant only.

Factors influencing cosmetic outcome and complication risk after conservative surgery and radiotherapy for early-stage breast carcinoma.

PURPOSE: The study was undertaken to assess the relationship among cosmesis and complications to factors related to disease presentation, surgical and radiotherapeutic technique, and adjuvant systemic therapy in conservative treatment for early-stage breast carcinoma. PATIENTS AND METHODS: Between 1982 and 1988, 234 women with stage I/II breast carcinoma were treated with conservation therapy by a highly standardized protocol of limited excision and radiotherapy. Radiation boost and/or reexcision were determined by careful quantitation of the normal tissue margin around the primary tumor. Boosts to 20 Gy were preferentially performed with interstitial iridium-192 (192Ir) implants. Axillary node dissections were performed in all patients aged less than 70 years. Adjuvant therapy consisted of cyclophosphamide, methotrexate, (doxorubicin), and fluorouracil (CM[A]F) six to eight times for node-positive premenopausal women and tamoxifen for node-positive or -negative postmenopausal women. Median follow-up was 50 months (range, 20 to 80 months). Cosmesis was graded by defined criteria, and complications were individually scored. RESULTS: Factors found to impact cosmesis adversely were palpable tumors (P = .046), volume of breast tissue resected (P = .027), reexcision of the tumor bed (P = .01), number of radiation fields (P = .03), radiation boost (P = .01), and chest wall separation (P = .01). There was a trend toward worse cosmesis (P = .062) in patients receiving tamoxifen. Cosmesis was not adversely affected by interstitial implant in spite of a higher prescribed dose. Factors influencing complication risk were axillary node dissection (P = .02), number of lymph nodes harvested (P = .05), and chemotherapy (P = .03). CONCLUSIONS: Optimal cosmesis and minimal complication risk require careful attention to the technical details of surgery and radiotherapy. The impact of systemic therapies needs to be more thoroughly examined.

Variation of corticosteroid-induced inhibition of collagen synthesis at equivalent anti-inflammatory doses.

At equivalent anti-inflammatory doses of corticosteroids, granuloma growth is not linearly related to the inhibition of granuloma collagen synthesis. However, the inhibition of granuloma collagen synthesis is linearly related to the inhibition of skin collagen synthesis. Therefore the decrease of collagen synthesis by corticosteroids is not related to anti-inflammatory activity but is related to the specific corticosteroid used.

Anti-inflammatory adrenal steroids that neither inhibit skin collagen synthesis nor cause dermal atrophy.

Clinically used topical anti-inflammatory adrenal steroids inhibit skin collagen synthesis. This impaired collagen synthesis may result in dermal atrophy. Structure activity studies contrasted the effects of the novel prednisolone derivatives, methylprednisolonate , and methyl 20 dihydroprednisolonate , with presently used anti-inflammatory adrenal steroids on granuloma formation and skin collagen synthesis. These two new prednisolone derivatives, when applied locally at equivalent-potency anti-inflammatory doses compared with other corticosteroids, markedly inhibit granuloma formation but do not inhibit skin collagen synthesis nor cause dermal atrophy in rats. The data indicate that the two prednisolone acid methyl esters may be safer topical anti-inflammatory adrenal steroids to use, since they do not inhibit normal skin collagen synthesis.

Dexamethasone decreases the amounts of type I procollagen mRNAs in vivo and in fibroblast cell cultures.

Dexamethasone treatment of neonatal chicks resulted in a time- and dose-dependent selective decrease of skin collagen synthesis. Total RNA of chick skin was isolated and hybridized to the cloned cDNAs pCg54 for pro-alpha 1 (I) mRNA and pCg45 for pro-alpha 2(I) mRNA. RNA isolated from the total skin of chicks receiving various doses of dexamethasone had dose-related decreases of pro-alpha 1 (I) and pro-alpha 2(I) mRNAs. The decrease of type I procollagen mRNAs for various doses of dexamethasone were similar to the decreases observed for collagen synthesis in vivo. Dexamethasone treatment of chick skin and chick lung fibroblasts resulted in a selective decrease of procollagen synthesis. A dose-related decrease of procollagen synthesis was observed with chick skin fibroblasts. Dexamethasone-treated chick skin and chick lung fibroblasts had decreased levels of pro-alpha 1 (I) and pro-alpha 2(I) mRNAs as determined by solid support hybridization with pCg54 and pCg45. The dexamethasone-mediated decreases of type I procollagen mRNAs in skin fibroblasts and lung fibroblasts were similar to the decreases observed in procollagen synthesis.

Bleomycin-induced increase of collagen turnover in IMR-90 fibroblasts: an in vitro model of connective tissue restructuring during lung fibrosis.

Late-log-phase IMR-90 human fetal lung fibroblasts were incubated with bleomycin sulfate for 48 hr. The culture medium was removed and replaced with serum-free medium and [5-3H]proline. The cells were then incubated for increasing time intervals. The cells and culture medium were collected, and radioactive proline incorporated into collagen and noncollagen protein was determined. Intracellular collagen synthesis was selectively increased. Furthermore, polysomes isolated from bleomycin-treated cells synthesized significantly more collagen in the wheat germ lysate than did control polysomes. Prolyl hydroxylase activity was also increased significantly in the bleomycin-treated cells. Free and peptide-bound radioactive hydroxyproline in the cells and medium was greatly increased in bleomycin-treated cells, which indicates increased collagen degradation. The results demonstrate that, although collagen synthesis in lung fibroblasts is increased by bleomycin, the newly synthesized collagen is rapidly degraded in both the cell layer and the medium. This increased collagen degradation may be responsible for the remodeling which takes place during lung fibrosis.

Inhibition of collagen accumulation by glucocorticoids in rat lung after intratracheal bleomycin instillation.

Male Fischer 344 rats were given a single lung instillation of bleomycin sulfate (0.6 units/100 g). some animals were treated 24 hr after bleomycin administration with triamcinolone diacetate. Steroid treatment was continued on alternate days for 4 weeks. At the end of 4 weeks, the lungs of rats receiving bleomycin alone had two-fold increases of both prolyl hydroxylase activity and proteinaceous hydroxyproline as compared to control values. The lungs of bleomycin-treated rats which received 4 mg of triamcinolone diacetate per kg on alternate days had a 33% increase of prolyl hydroxylase activity and proteinaceous hydroxyproline content of bleomycin-treated animals receiving glucocorticoid (8 mg/kg) on alternate days were the same as control values. The results indicate that alternate day administration of the synthetic glucocorticoid triamcinolone diacetate blocks lung collagen accumulation following a single intratracheal dose of bleomycin to rats.

Collagen lysyl oxidase activity in the lung increases during bleomycin-induced lung fibrosis.

Intratracheal administration of bleomycin caused pulmonary fibrosis in rats. Bleomycin sulfate (640 micro grams/165 g b.wt. in 0.5 ml of sterile saline) was instilled Intratracheally into male Fisher 344 rats (169 +/- 5 g), whereas control animals received 0.5 ml of sterile saline by the same route. One, 3, 7, 14, 28 and 322 days after instillation, the animals were killed, the lungs were homogenized in 6 M urea, 0.01 M NaCl, 0.001 M potassium phosphate (pH 8.3) and the homogenates were subjected to ultracentrifugation. The 106,000 x g supernate was assayed for lysyl oxidase activity. Total lung hydroxyproline and desmosine content was determined at each time point. Lysyl oxidase specific activity in the lung was elevated significantly 3 days after bleomycin treatment, peaked 14 days after bleomycin treatment at 230% above the control value and was returned toward normal 28 days after treatment. The increase of lysyl oxidase activity preceded the maximal increase of total lung hydroxyproline and desmosine which occurred 28 days after bleomycin instillation.