Lung cancer is one of the leading causes of the cancer death worldwide. Gefitinib is an inhibitor of the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) and has been ...introduced in the treatment of advanced lung cancers. The responsiveness to gefitinib has been linked to the presence of EGFR mutations. Clinical samples contain many normal cells in addition to cancer cells. A method capable of detecting EGFR mutations in a large background of wild-type EGFR genes could provide a superior clinical test. We developed a rapid and sensitive detection system for EGFR mutations named the peptide nucleic acid-locked nucleic acid (PNA-LNA) PCR clamp that can detect EGFR mutations in the presence of 100-to 1,000-fold background of wild-type EGFR. We used this method to screen 30 non-small cell lung cancer cell lines established from Japanese patients. In addition to 11 cell lines that have mutations, we found 12 cell lines in which specific mutations are observed only in the subpopulation(s) of the cells. Genetic heterogeneity of EGFR suggests that the EGFR gene is unstable in established cancers and the heterogeneity may explain variable clinical responses of lung cancers to gefitinib.
Mutations in the epidermal growth factor receptor (EGFR) are observed in a fraction of non‐small‐cell lung cancers (NSCLS). EGFR mutation‐positive NSCLS responds to gefitinib. Secondary T790M ...mutation confers gefitinib resistance to NSCLS. A detection test for the T790M mutation was designed based on the peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp method. The specificity and sensitivity of the test were both greater than 0.99. The test revealed that only a small population of the PC‐13 cells carried the T790M mutation. The test also revealed that the T790M mutation was found in none of 151 NSCLC specimens obtained before gefitinib treatment, whereas it was found in four of four specimens obtained from NSCLS that had become refractory to gefitinib. In one patient in whom the L858R‐positive EGFR allele was amplified to multiple copies, an L858R‐T790M double‐mutant allele emerged during the gefitinib therapy. This allele was expressed highly. The T790M mutation detection test based on the peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp method is sensitive and specific, and is applicable to clinical practice. It detects T790M‐positive cells in the course of gefitinib treatment, and thus will help to devise therapies effective for T790M‐positive NSCLS. (Cancer Sci 2008; 99: 595–600)
Gefitinib is an inhibitor of the tyrosine kinase activity of epidermal growth factor receptor (EGFR). Accumulating evidence suggests that gefitinib may provide a survival benefit to EGFR ...mutation‐positive non‐small lung cancer patients. We have established a clinical test that can detect EGFR mutations from cytological specimens or paraffin‐embedded tissue specimens that are contaminated by normal cells. This test is based on the peptide nucleic acid, locked nucleic acid polymerase chain reaction clamp method that can detect G719S, G719C, L858R, L861Q and seven different exon 19 deletions in the presence of 100–1000‐fold wild‐type alleles. Consequently, using a small aliquot of samples isolated to establish a cancer diagnosis, the EGFR mutation status is determined soon after the diagnosis of cancer is made. We investigated the EGFR mutation status in 86 patients using a variety of cytological specimens (59 bronchoscopy specimens, 16 pleural effusion, 9 sputum, and 2 pericardial effusion) and in 46 patients who had a disease relapse and paraffin‐embedded tissues were available. Forty‐five patients (34%) were positive for mutation (29 exon 19 deletions, 16 L858R and 1 L861Q). The sensitivity and the specificity of this test was 97% and 100%, respectively. EGFR mutation status thereby obtained was used to determine each patient's therapeutic regimen. This test is easily integrated into the normal clinical practice for lung cancer, while allowing the medical staff to select therapeutic regimen depending on the EGFR mutation status. (Cancer Sci 2007; 98: 246–252)
Background: Serum CA15-3 has been one of the most reliable tumor markers used in monitoring breast cancer patients; however, its sensitivity in detecting metastases is limited. To increase its ...sensitivity, the combined measurement of other tumor markers with CA15-3 was investigated. Methods: Serum CA15-3, carcinoembryonic antigen (CEA) and sialyl Lewis X (CSLEX) were simultaneously measured in a prospective series of 455 postoperative breast cancer patients with or without metastasis. The diagnostic parameters sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting metastases were compared. The correlation of values between pairs of tumor markers was analyzed. The efficacy of combined measurement of two different tumor markers was also evaluated. Results: The sensitivity for detecting metastases was 61.5, 56.9 and 52.3%; specificity was 97.2, 93.6 and 96.2%; PPV was 78.4, 59.7 and 69.4%; NPV was 93.8, 92.9 and 92.4%; and accuracy was 92.1, 88.8 and 89.9% for CA15-3, CEA and CSLEX, respectively. The values for CA15-3 were significantly correlated with those for CEA (P < 0.001) but not those for CSLEX. The combined measurement of CSLEX and CA15-3 increased the sensitivity by 17.0% but that of CEA and CA15-3 increased the sensitivity by only 10.8%. All diagnostic parameters for the combined measurement of CSLEX and CA15-3 were higher than those for the combined measurement of CEA and CA15-3. Conclusions: These findings suggest that CSLEX may be more useful than CEA in combination with CA15-3 in monitoring breast cancer patients. The results of this study suggest that CSLEX may be more useful than CEA in combination with CA15-3 in monitoring breast cancer patients.
We report a unique case of metastatic papillary thyroid carcinoma of the submandibular lymph nodes with extensive squamous metaplasia. A 48-year-old man was referred to our hospital for treatment of ...a thyroid tumor and right submandibular masses. A tumor, 2 cm in its largest dimension, was palpated in the right lobe of the thyroid gland. The masses in the submandibular region measured up to 3 cm in diameter. Each submandibular tumor had a cystic cavity containing slightly opaque fluid. Aspiration cytology of the thyroid established a diagnosis of papillary carcinoma. Aspirated material from the cystic cavity of one of the submandibular masses contained only keratinized material with a thyroglobulin level of 175 ng/ml. The patient underwent a total thyroidectomy with modified radical neck dissection. Microscopic examination of the resected specimen confirmed a diagnosis of papillary carcinoma of the thyroid, as well as well-differentiated squamous cell carcinoma with cystic changes in the submandibular lymph nodes. Focal immunoreactivity for thyroglobulin, combined with the absence of any other possible primary lesions in the head and neck region, suggested metastatic papillary thyroid carcinoma of the submandibular lymph nodes with extensive squamous metaplasia.
Thymidilate synthase (TS) is a major target of 5-fluorouracil (5-FU) and dihydropyrimidine dehydrogenase (DPD) is a rate-limiting enzyme in the degradation of 5-FU. Intratumoral activity and ...expression levels of both enzymes are suggested to be predictive markers for response to 5-FU-based chemotherapy in cancer patients. Several different methods are used to measure intratumoral levels of TS and DPD. We developed new enzyme-linked immunosorbent assays (ELISAs) for these enzymes. New ELISAs were produced using anti-TS and anti-DPD polyclonal antibodies obtained using recombinant human TS and purified DPD from pig liver, respectively. Intra-assay coefficients of variations (CVs) were less than 5% in both ELISAs. Inter-assay CVs tested using the extract from 20 breast cancer specimens were 1.5-24.2% for TS-ELISA and 0.4-7.2% for DPD. Importantly, TS and DPD levels measured by the respective ELISAs closely related to TS activity (r(2)=0.8492) and DPD activity (r(2)=0.7666), respectively, measured by the respective substrate assays. To investigate the correlations between clinicopathological characteristics and intratumoral TS and DPD levels, data on 52 breast cancer patients were analyzed. Estrogen receptor (ER)-negative tumors had significantly higher TS and DPD levels than ER-positive tumors. Progesterone receptor (PgR)-negative tumors showed a significantly higher DPD level than PgR-positive tumors. There was no significant correlation of the TS or DPD levels with other clinicopathological factors in this preliminary study. Further studies are warranted to investigate predictive and prognostic values of intratumoral TS and DPD levels in various malignancies using these ELISAs.
Although adverse reactions to local anesthetics are often diagnosed as local anesthetic allergy, there is evidence that most of these reactions occur via non-allergic mechanisms.
To evaluate allergic ...reactions to local anesthetics, challenge tests were performed in 20 patients who had a history of adverse events to local anesthetics for whom dental treatment was planned. The diagnostic protocol of this challenge test consisted of skin prick and intracutaneous tests, as well as subsequent incremental subcutaneous challenge tests with local anesthetics such as lidocaine.
17 patients (85%) showed no immediate allergic response to lidocaine, which could then be used for dental treatment. Three patients (15%) reacted positively to lidocaine: one had local erythema at the site of the skin prick, and two reacted to subcutaneous challenge.
The proportion of immediate-type reactions to local anesthetics is small but not rare in patients suspected of having local anesthetic allergy. This result suggests that the diagnostic approach to confirm allergy to local anesthetics is clinically important and requires further study in a larger population.
The aim of this study is to assess surgical margin status, which is an important factor as a cause of local failure after breast conserving treatment (BCT) and to evaluate the utility of probe ...lumpectomy (PL). Subjects were 78 cases treated by BCT at the hospital between 1993 and 1999. PL was carried out under local anesthesia. In PL the tumor was resected with a normal tissue margin of 15mm from areolar side and 10mm from the other side. We examined the extent of cancer using multiple sections of surgical specimens. After 7 days when pathological surgical margin was positive, we carried out reexcision with axillary dissection or mastectomy. When margin was negative, we performed only axillary dissection under general anesthsia. Positve final rates of overall, PL and non-PL were 21.8%, 6.1% and 33.3%, respectively (PL vs. non-PL p<0.0005). Two patients who had done non-PL and also had positve margin suffered from local recurrence. The outcomes of modalities such as magnestic resonance imaging, CT or frozen section diagnosis to predict the extent of cancer before or during operation were insufficent. Knowing the information of cancerous extent correctly using PL before BCT is useful not only to get negative final margin but also to obtain the informed consent.
To investigate the levels of expression of the sodium iodide symporter (NIS) and three differentiation markers (thyroglobulin (Tg), thyroid peroxidase (TPO) and thyrotrophin receptor (TSH-R)) in 35 ...patients with primary (n=31) or recurrent (n=4) papillary thyroid carcinoma, and to compare the findings with clinical data.
We performed a multiplex semi-quantitative RT-PCR to analyse the relative levels of expression of Tg, TPO and TSH-R mRNAs, and a separate semi-quantitative RT-PCR for NIS mRNA.
Tg, TPO and TSH-R mRNAs were expressed in all the patients, whereas NIS mRNA was expressed in all but eight. Analysis of the expression of the differentiation markers in all patients showed a significant correlation among Tg, TPO and NIS. With regard to the relationship between the expression of each gene and the MACIS score, there was significant correlation only for the Tg gene (P<0.05).
The levels of expression of NIS mRNA correlated significantly with those of Tg and TPO mRNAs, but not with those of TSH-R mRNA. The relationship with clinical stage and prognostic score, however, varied among these differentiation markers.
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