Photodynamic therapy for multiple central type lung cancer - a case report.

In case of central type lung cancer, it happens that tumors tend to grow at many foci of bronchial tree, sometimes simultaneously and sometimes not. And these patients with such abnormalities often suffer from pulmonary emphysema or chronic bronchitis because of heavy smoking habits. So it is important to choose the treatment which preserve the pulmonary function in these cases. Today among several kinds of treatments, photodynamic therapy (PDT) is the definite method to maintain lung function. We report here a case of multiple central type lung cancer treated successfully by PDT.

New aspects of photodynamic therapy for central type early stage lung cancer.

BACKGROUND: and Objective Photodynamic therapy (PDT) has come to be considered as the first choice of treatment for central type early stage lung cancer (CELC). Recent advances in the ability to diagnose CELC, and in photosensitizers, as well as sophisticated clinical management, may improve the therapeutic outcome and expand the indications of PDT. MATERIALS AND METHODS: We made the search for papers on PDT for lung cancer to select the most relevant articles. Based on this review and our recent data, we discussed the best available evidence for the diagnosis, the definition of indications, photosensitizers, and clinical management with regard to PDT. RESULTS: To obtain complete response (CR) by PDT, the selection of the indications is extremely important, including the extent of the tumor on the bronchial surface and the depth of invasion in the bronchial wall. The development of autofluorescence bronchoscopy (AFB) and endobronchial ultrasonography (EBUS) have had a large impact on diagnostic bronchoscopy for CELC. CELCs less than 1 cm in diameter showed a favorable cure rate by PDT, thus this is a good indication for PDT. The relatively newer photosensitizer NPe6, which has a stronger antitumor effect than Photofrin, showed similar treatment outcome even for large tumors >1.0 cm in diameter. Furthermore, comprehensive management including photodynamic diagnosis before and after PDT should be effective to minimize the possibility of local recurrence after PDT. CONCLUSION: The present guidelines of PDT for CELC were established based on the data obtained from studies in the 1980's. We postulate that comprehensive diagnosis and the new generation of photosensitizers may increase the CR rate and expand the indications of PDT for larger tumors.

Breast cancer resistant protein (BCRP) is a molecular determinant of the outcome of photodynamic therapy (PDT) for centrally located early lung cancer.

The ATP-binding cassette (ABC) transporter protein, BCRP (breast cancer resistance protein)/ABCG2 pumps out some types of photosensitizers used in photodynamic therapy (PDT) and causes resistance to the antitumor effect of PDT. The purpose of this study was to investigate the association between the expression of BCRP and the efficacy of PDT using Photofrin, or the second-generation photosensitizer, NPe6, for centrally located early lung cancers. Using human epidermoid carcinoma cells, A431 cells and the BCRP-overexpressing A431/BCRP cells, we examined the effects of BCRP expression on the effect of PDT by cell viability assay in vitro, and investigated the expression of BCRP by immunohistochemical analysis in 81 tumor samples obtained from patients with centrally located early lung cancers. The A431/BCRP cells were more resistant to Photofrin-PDT than A431 cells in vitro, and Fumitremorgin C, a specific inhibitor of BCRP, reversed the resistance. However, there was no significant difference in the antitumor effect of NPe6-PDT between these cells. All of the 81 centrally located early lung cancer lesions were BCRP-positive (2+, 45 lesions; 1+, 30 lesions) and all the patients were male and heavy smokers (>30 pack-years). The expression of BCRP significantly affected the efficacy of Photofrin-PDT in cancer lesions > or =10mm in diameter (P=0.04). On the other hand, NPe6-PDT exhibited a strong antitumor effect, regardless of the expression status of BCRP. Photofrin may be a substrate of BCRP and be pumped out from the cells, therefore, BCRP may be a molecular determinant of the outcome of Photofrin-PDT.

Tailor-made approach to photodynamic therapy in the treatment of cancer based on Bcl-2 photodamage.

It is very important to elucidate the mechanism of action and identify the molecular determinant of photodynamic medicine, in order to increase the number of clinical applications of photodynamic therapy (PDT) and perform personalized medicine. We have previously reported that PDT using some photosensitizers, such as phthalocyanine 4 (Pc 4) damages the anti-apoptotic protein Bcl-2, and that Bcl-2 is a molecular PDT target using a mitochondrion-targeting photosensitizer. In this study, we examined the molecular targets of Photofrin-PDT and NPe6-PDT, which are approved for early stage lung cancers by the Japanese Ministry of Health Labor and Welfare, by evaluating the photodamage to Bcl-2 using Western blot analysis. Our results showed that Photofrin-PDT damaged Bcl-2, induced morphologically typical apoptosis, and demonstrated equal sensitivity between MCF-7c3 cells (human breast cancer cells expressing stably transfected procaspase-3) and Bcl-2 overexpressing cells, MCF-7c3-GFP-Bcl-2 cells, with a clonogenic assay. However, NPe6-PDT did not damage Bcl-2 and took longer to induce typical apoptosis compared with Photofrin-PDT. MCF-7c3-GFP-Bcl-2 cells were considerably more resistant to the lethal effects of NPe6-PDT than parental MCF-7c3 cells. In conclusion, Photofrin-PDT damages different molecular targets, and our data indicate that the extent of Bcl-2 photodamage can determine the sensitivity of cancer cells to apoptosis and to overall cell killing caused by PDT using Photofrin, but not the lysosomal targeting NPe6. The application of these findings to clinical PDT may depend on the levels of the Bcl-2 proteins in the tumor being treated, and the tailor-made medicine based on the Bcl-2 photodamage may overcome any resistance afforded by elevated amounts of Bcl-2.

Photodynamic therapy for lung cancers based on novel photodynamic diagnosis using talaporfin sodium (NPe6) and autofluorescence bronchoscopy.

BACKGROUND: We had previously developed the possibility of use of a photodynamic diagnosis (PDD) system using a tumor-selective photosensitizer and laser irradiation for the early detection and photodynamic therapy (PDT) for centrally located early lung cancers. Recently, we established the autofluorescence diagnosis system integrated into a videoendoscope (SAFE-3000) as a very useful technique for the early diagnosis of lung cancer. PATIENTS AND METHODS: Twenty-nine patients (38 lesions) with centrally located early lung cancer received PDD and PDT using the second-generation photosensitizer, talaporfin sodium (NPe6). Just before the PDT, we defined the tumor margin accurately using the novel PDD system SAFE-3000 with NPe6 and a diode laser (408nm). RESULTS: Red fluorescence emitted from the tumor by excitation of the photosensitizer by the diode laser (408nm) from SAFE-3000 allowed accurate determination of the tumor margin just before the PDT. The complete remission (CR) rate following NPe6-PDT in the cases with early lung cancer was 92.1% (35/38 lesions). We also confirmed the loss of red fluorescence from the tumors immediately after the PDT using SAFE-3000. We confirmed that all the NPe6 in the tumor had been excited and photobleached by the laser irradiation (664nm) and that no additional laser irradiation was needed for curative treatment. CONCLUSIONS: This novel PDD system using SAFE-3000 and NPe6 improved the quality and efficacy of PDT and avoided misjudgement of the dose of the photosensitizer or laser irradiation in PDT. PDT using NPe6 will become a standard option of treatments for centrally located early lung cancer.

Lysosomal cathepsin initiates apoptosis, which is regulated by photodamage to Bcl-2 at mitochondria in photodynamic therapy using a novel photosensitizer, ATX-s10 (Na).

ATX-s10 is a novel and second-generation photosensitizer for photodynamic therapy (PDT). In order to conduct clinical trials of ATX-s10-PDT and/or extend its clinical applications, it is very important to elucidate the mechanisms of the action of ATX-s10-PDT. We examined the apoptic response against ATX-s10-PDT using a Bcl-2 or Bcl-2 mutant overexpressing cells. Using fluorescent microscopy, ATX-s10 localized not only to mitochondria but also to lysosomes and possibly other intracellular organelles, but not to the plasma membrane or the nucleus. These results suggest that ATX-s10-PDT can damage mitochondria and lysosomes. By Western blot analysis, ATX-s10-PDT damaged Bcl-2, which localized preferentially at mitochondrial membranes, and caused Bcl-2 to cross-link immediately after laser irradiation. However, ATX-s10-PDT was not able to rapidly induce morphologically typical apoptosis (i.e. chromatin condensation and fragmentation) as PDT using mitochondria targeted photosensitizers, such as phthalocyanine 4 (Pc 4). Pharmacological inhibitions of lysosomal cytokine protease cathepsins, such as cathepsin B and D, protected MCF-7c3 cells (human breast cancer cells expressing stably transfected procaspase-3) from apoptosis caused by ATX-s10-PDT. Overexpression of wild-type Bcl-2 or Bcl-2Delta33-54 resulted in relative resistance of cells to ATX-s10-PDT, as assessed by the degree of morphological apoptosis or loss of clonogenicity. We conclude that lysosomal damage by ATX-s10-PDT can initiate apoptotic response and this apoptotic pathway can be regulated by photodamage to Bcl-2 via mitochondrial damage.

Photodynamic therapy (PDT) for lung cancers.

Photodynamic therapy (PDT), a treatment for cancer, uses a photosensitizer and laser irradiation to produce reactive oxygen in cells. In Japan, the United States, and many other countries, PDT is a treatment option for stage 0 (TisN0M0) and stage I (T1N0M0) centrally located early stage lung cancer. PDT can preserve lung function, can be repeated, and can be combined with other therapeutic modalities such as chemotherapy. Recently, mono-l-aspartyl chlorine e6 (NPe6, Laserphyrin), a second-generation photosensitizer with lower photosensitivity than Photofrin (porfimer sodium), was approved by the Japanese government and a phase II clinical study using NPe6 with a new diode laser demonstrated an excellent antitumor effect and low skin photosensitivity. We expect PDT to be widely employed in many fields and the applications of PDT to be extended because of the decreasing cost of laser equipment and lower systemic photosensitivity induced by the photosensitizer. The purpose of this review is to introduce not only recent clinical trials of PDT for centrally located early lung cancer, but also new applications of PDT for cases of peripheral-type, early-stage lung cancers. We also discuss the applications of PDT for advanced lung cancer and combined therapy using PDT and other treatments for lung cancer.

Locally recurrent central-type early stage lung cancer < 1.0 cm in diameter after complete remission by photodynamic therapy.

BACKGROUND: It is well known that central-type early stage lung cancer < 1.0 cm in diameter shows almost 100% complete response (CR) to photodynamic therapy (PDT). However, we have encountered cases of local recurrence after CR of tumors with a surface diameter < 1.0 cm. PATIENTS AND METHODS: Ninety-three patients with 114 lesions were followed up, and cases of recurrence after CR has been obtained with initial tumors that had a diameter < 1.0 cm were examined. We compared the cytologic findings of local recurrence after CR to the cytologic findings before PDT. The relationship between the cell features and the depth of bronchial tumor invasion before PDT and on recurrence was evaluated. RESULTS: The CR and 5-year survival rates of patients with lesions < 1.0 cm were 92.8% (77 of 83 patients) and 57.9%, respectively; meanwhile, in the group of patients with lesions > or = 1.0 cm, CR and 5-year survival rates were 58.1% (18 of 31 patients) and 59.3%. There was a significant difference in efficacy between the two groups (p < 0.001). Recurrences after CR were recognized in 9 of 77 lesions (11.7%) < 1.0 cm. When the recurrent tumor cells showed type I-II (low-to-moderate atypia) at the same site initially treated, CR could be obtained by a second PDT. Type III cells (high-grade atypia) showed the characteristics of tumor cells from deeper layers of the bronchial wall. Local recurrence at the same site may be caused by residual tumor cells from deep layers because of inadequate laser irradiation and penetration. CONCLUSIONS: To reduce the recurrence rate, it is essential to accurately grasp the tumor extent and the depth of the bronchogenic carcinoma before performing PDT. Analysis of cell features of recurrent lesions after CR appears to be a useful source of information as to the depth of cancer invasion in the bronchial wall.

Postoperative adjuvant therapy for completely resected early-stage non-small cell lung cancer.

Consensus on adjuvant therapy for completely resected non-small cell lung cancer until 2002 was as follows. (1) There was no significant impact of postoperative adjuvant chemotherapy based on meta-analysis and previous clinical trials. (2) Confirmatory studies are necessary in large-scale prospective clinical trials. However, recent mega trials have introduced epoch-making changes for postoperative adjuvant chemotherapy in clinical practice since ASCO 2003. The effectiveness of UFT in N0 patients was confirmed. Patients with completely resected stage I non-small cell lung cancer, especially T2N0 adenocarcinoma, will benefit from adjuvant chemotherapy with UFT. The results of the International Adjuvant Lung Trial (IALT) have confirmed the meta-analysis in 1995. Also, both the JBR10 and Cancer and Leukemia Group B (CALGB) 9633 studies have also confirmed positive IALT results of the benefit for postoperative platinum-based chemotherapy in completely resected non-small cell lung cancer. Adjuvant chemotherapy for pathological stage IB to II, completely resected non-small cell lung cancer is standard care based on clinical trials. UFT showed the strongest evidence for IB in Japan. Platinum doublet chemotherapy with third-generation anticancer agents is also recommended. Adjuvant chemotherapy should be offered as standard care to patients after completely resected early stage non-small cell lung cancer. However, there is no evidence of the feasibility and efficacy for adjuvant chemotherapy with the platinum-based regimen in Japan. Careful management should be necessary in such treatment.

Present strategy of lung cancer screening and surgical management.

Previous lung cancer screening trials in the United States (US) employing chest X ray and sputum cytology did not demonstrate reductions in lung cancer mortality. However, recent case control studies in Japan demonstrated a decrease in lung cancer mortality in the computed tomography (CT) screened group. Lung cancer screening using chest CT detected more cancers at an earlier stage than chest X ray. Before CT screening is widely performed, lung cancer mortality reduction should be proved in a scientific manner. The problem of a much higher false positive rate of this method should be solved. The subtypes of adenocarcinoma; bronchioloalveolar carcinoma (BAC) tends to show specific CT findings called ground glass opacity (GGO) and a favorable prognosis can be expected. BAC is usually invisible by chest X ray and detected only by CT. Recent studies have shown the proportion of GGO is strongly related to biological malignancy of small adenocarcinoma. Based on this fact, thoracic surgeons wish to identify the possibility of limited resection for minimally invasive cancers. Lung cancer researchers are interested in evaluating the nature of small adenocarcinoma as well as the carcinogenic process. A comprehensive understanding of screening-detected cancers including the CT images, pathology and genetic analysis is necessary for optimum management of such nodules.

Photodynamic therapy for peripheral lung cancer.

Photodynamic therapy (PDT) has now achieved the status of a standard treatment modality for centrally located early-stage lung cancer. In the last decade, CT screening for lung cancer has attracted much attention for its ability to detect early peripheral lung cancer. Extremely recently, treatment using PDT has been introduced for the first time in patients with peripheral lung cancer, who did not meet the previous criteria for surgery. The procedure was carried out with local anesthesia with xylocain infiltrated into the chest wall, 48 h after Photofrin administration. Needles (19 gauge) containing an internal catheter were inserted percutaneously under CT guidance. The needles were then extracted and a diffuser fiber with a 2 cm long tip for light delivery was positioned in the tumor through the catheter. Of the nine patients enrolled in this trial, seven achieved partial remission (PR). No serious complications, except for two cases of pneumothorax, were noted. As an increasing number of patients consider quality of life after therapy, the indications for PDT are expected to expand. We conclude that PDT is a promising new technique for curative treatment of localized, peripheral lung cancer less than 1cm in size in patients who are unfit for surgery or radiotherapy.

Photodynamic therapy (PDT) of lung cancer: experience of the Tokyo Medical University.

Endoscopic low (Photodynamic therapy (PDT)) or high (vaporization) power laser treatment has been recognized as a lung-sparing local therapeutic modality that can achieve remarkable responses. This paper reviews the experience of our institution since 1978 in the treatment of lung cancer using laser. Endoscopic ablation of tracheobronchial malignancies is mainly intended to reduce respiratory distress and improve quality of life. Effective results were obtained in 143 (81%) of the 177 lesions. PDT is extremely attractive and has been used for the various purposes. In the curative PDT for centrally located early stage lung cancer, complete response (CR) rate was achieved in 86.4% (165 out of 191 lesions). Overall 5-year survival rate was 57.6% and the lung cancer specific 5-year survival rate was 92.5%. With regard to palliative PDT to opening obstructed bronchi in advanced cases, more than 50% opening of the obstruction was accomplished in 75%. Preoperative PDT was performed in 32 patients with lung cancer for the purpose of either reducing the extent of resection or increasing operability. The initial purpose of PDT was achieved in 27 of 32 patients treated. Conversion to an operable condition was achieved in 4 of 5 originally inoperable cases. In 23 of 27 patients who were originally candidates for pneumonectomy, it became possible to reduce the extent of resection to lobectomy or sleeve lobectomy. PDT could be used to treat peripheral tiny lung cancers safely and without unacceptable effects on surrounding tissue. The authors believe that PDT has a great potential and will achieve further development in the future.

Spectrometric characteristics and tumor-affinity of a novel photosensitizer: mono-l-aspartyl aurochlorin e6 (Au-NPe6).

Photodiagnosis and photodynamic therapy with photosensitizers can be indicated only for tumors of the superficial type, because these approaches utilizing visible light are limited by said light penetrability. To overcome this disadvantage, we innovated a novel photosensitizer, mono-l-aspartyl aurochlorin e6 (Au-NPe6), by incorporating a gold atom in the center of tetrapyrrole ring of NPe6 with a coordination bond. The gold atom in Au-NPe6 plays a role as an X-ray interceptor to detect deeply sited tumors. In this study, the absorption spectrum of novel Au-NPe6 in the diagnosis of deeply sited tumors was investigated, and the results were compared with the parent photosensitizer NPe6. Furthermore, the tumor-affinity of Au-NPe6 was evaluated using atomic absorption spectrometry. Despite the fact that both photosensitizers display a difference in the absorption spectrum, waveform changes of either photosensitizer with human serum albumin established a saturation point at a molar ratio of 1:1. The results indicate that it is highly possible that Au-NPe6 bound with albumin at a molar ratio (1:1) similar to NPe6. The accumulation rate of gold in tumor tissues was always significantly (p<0.05) higher than that in normal muscle tissues during the observation terms. Moreover, absorption spectra of tumor-tissue homogenates obtained from tumor-bearing mice after Au-NPe6 administration revealed a common peak with a wavelength equivalent to that of albumin-bond Au-NPe. This result suggests that the gold atom and NPe6 probably remained bonded even when Au-NPe6 was incorporated in tumor tissues.

Phase II clinical study of photodynamic therapy using mono-L-aspartyl chlorin e6 and diode laser for early superficial squamous cell carcinoma of the lung.

Photofrin is the most commonly used photosensitizer for photodynamic therapy (PDT). The major side effect of Photofrin is cutaneous photosensitivity. A second generation photosensitizer, mono-L-aspartyl chlorin e6 (NPe6) has shown anti-tumor efficacy and rapid clearance from skin. Therefore, we conducted a phase II clinical study to investigate the anti-tumor effects and safety of NPe6 in patients with early superficial squamous cell carcinoma of the lung. Enrollment criteria consisted of endoscopically evaluated early stage lung cancer with normal chest X-ray and CT images, no lymph node or distant metastasis. Tumors were located no more peripherally than subsegmental bronchi, the peripheral margin had to visible, and the tumor size had to not more than 2 cm in diameter. The histologic type of the tumor had to squamous cell carcinoma. Laser irradiation (100 J/cm2) using a diode laser was performed at 4 h after administration of NPe6 (40 mg/m2). Among 41 patients with 46 lesions, 40 with 45 lesions were eligible for safety evaluation, and 35 patients with 39 lesions were judged as eligible for efficacy evaluation. No serious adverse drug reactions were observed. Disappearance of skin photosensitivity was recognized within 2 weeks in 28 of 33 patients (84.8%) and in all the other seven patients first tested at 15-18 days. Complete response (CR) was seen in 84.6% of lesions (82.9% of patients). This study demonstrated excellent anti-tumor effects and safety, especially low skin photosensitivity in patients with early stage lung cancer. PDT using the second generation photosensitizer NPe6 and a diode laser will likely become a standard modality of PDT for central type early superficial squamous cell carcinoma of the lung.

Histopathological evaluation of fluorescence bronchoscopy using resected lungs in cases of lung cancer.

Objective evaluation of the performance of autofluorescence bronchoscopy based on analysis of thin sections of the bronchus of resected lungs was performed and compared with the results of preoperative autofluorescence bronchoscopy. Conventional bronchoscopy and autofluorescence bronchoscopy were performed prior to surgery for lung cancer. Thin sections of the bronchus were obtained from the resected specimens. The thin sections were pathologically analyzed and the diagnostic accuracy of endoscopy was calculated. The subjects were 30 consecutive operable lung cancer cases who received white light and autofluorescence bronchoscopy before operation. A total of 163 thin sections of the bronchi in the resected lungs were made. The sensitivity of white light bronchoscopy for cancer was 90 and 31% for dysplasia. The respective figures for autofluorescence bronchoscopy were 97 and 50% for cancer and dysplasia. The specificity of white light and autofluorescence was 88 and 84%, respectively. The diagnostic accuracy of autofluorescence bronchoscopy was objectively confirmed. Autofluorescence examination showed better sensitivity for cancerous/precancerous lesions and the evaluation of the extent of cancer invasion was accurate.

[Photodynamic therapy for lung cancer: state of the art and expanded indications].

Photodynamic therapy (PDT) has now achieved the status of a standard treatment modality for centrally located, early-stage lung cancer and is introduced on the home page of the US National Cancer Institute. Over the past decade, 145 patients (191 lesions) with central-type early-stage lung cancers have been treated with PDT in our hospital. Overall complete remission was obtained in 86.4% of the total number of lesions. In patients with advanced stage III disease, however, bronchi opening was successful in 61 out of 81 lesions (75%) for the PDT group compared with 143 of 177 (81%) in the Nd-YAG laser therapy group. Although quite recent, treatment using PDT has been introduced for the first time in patients with peripheral lung cancer, who did not previously meet the criteria for surgery. Eight patients underwent this trial, of which 3 achieved partial remission. No serious complications except for one case of pneumothorax, were noted. As increasing number of patients consider quality of life after therapy, the indications for PDT are expected to expand. The success in clinical trials of PDT for cancer treatment offers encouragement for its future use.