The Study And Clinical Significance Of Microsatellite Loss Of Heterozygosity In Primary Laryngeal Squamous Cell Carcinomas And Recurrence Of Laryngeal Squamous Cell Carcinomas

[Background and purpose]Head and neck cancer occurrence in the body tumor incidence is the sixth.But, laryngeal squamous cell carcinomas is a common malignant tumor of head and neck, its incidence accounts for 5.7%-7.6% in systemic cancer, its incidence accounts for 7.9%～35% in head and neck cancer incidence. In rescent years, the morbidity and mortality of Laryngeal cancer were significantly higher, it is serious threat to human health and life. Despite the continuous improvement of the clinical improvement of various surgical methods, Light side effects of radiotherapy and chemotherapy programs have emerged,but patients with laryngeal cancer is still a considerable number of local or regional transfer of postoperative, Or even systemic metastases. Recurrence of laryngeal cancer is still the main reason for treatment failure, Some research report that about 50% of recurrence rate, recurrence site include the local throat, regional lymph node and distant metastasis. With in-depth study of laryngeal cancer, different types of laryngeal cancer have a deeper understanding of the law of development and its prognostic factors has been further explored, so that clinical treatment has also changed. At present, the study of recurrent laryngeal cancer in patients with primary or recurrent cancer is very less,In particular, these so-called "recurrent" tumor is a recurrence tumour which tumour has the same origin with the primary cancer or is a second primary cancer who not has same origin with the primary cancer, which was always been remain a pending issue. Traditionally, clinicopathologic evidence has been the gold standard used to distinguish distant metastasis from second primary tumors in the same patient. However, if the pathology types was consistent that recurrent or second primary tumor can not be judged, And accurately distinguish the tumour which was the so-called recurrent tumour was primary cancer recurrence or second primary cancer is the premise to reveal the law of tumor occurrence and development,and ultimately find an effective method to overcome the tumor.More than 98% in Larynx and hypopharynx cancer is squamous cell carcinoma,that often with cervical lymph node metastasis, especially in supraglottic and hypopharynx cancer. Cervical lymph node metastasis rate in larynx and hypopharynx cancer was high up to 60%. The traditional neck dissection has been considered an effective method to removal of the cervical lymph node metastasis. However, there are still more patients with laryngeal cancer recurrence whose pathological examination of lymph node was negative after routine neck dissection. The 5-year neck tumour recurrence rate was 10% to 15%, consider that the reason is failed to removal of lymph node micrometastases or different clonal origin of the second primary tumor. This means that routine pathological examination is difficult to find a single cell or small cell clusters form small metastases or second primary tumor, these occult metastasis that are not be easy founded by general inspection methods may be the main cause of recurrence and metastasis. It is also affect the development of comprehensive treatment programs and indirectly affect the patient’s prognosis."Field cancerization," the hypothesis is that although epithelial cells within the region show normal appearance, but they have cancerous conditions in advance due to the slow effect of exposure to carcinogens, when the conditions change to promote their gradual change into invasive disease, and regional mucosal lesions may exist in different locations at different times. That is, the primary tumor may appear next to the satellite second primary cancers, their distribution is not a specific location. Micrometastases in lymph nodes are not clustered, but scattered unspecific location throughout the lymph nodes in the distribution in the lymph nodes do not have a specific. It is because of micro-metastases and possible location of the second primary tumors are not certainly, the researchers in the use of serial sections of HE staining in order to improve accuracy. Viale and other reports, the interval of 50um serial sections can be found 18% of micrometastases, after the increaseing up to 300um will be left out. Dowlatsha hi and other reports,52 patients with stage I or II breast cancer 0.25mm line spacing for serial section and add IHC, the detection rate of transfer from 12% to 58%. Xu ShiYing statistical detection of micrometastasis of the 29 smallest diameter (1.36±0.85)mm, recommended lmm slice interval as a routine operational. But making real serial sections need much time-consuming, how many facets of a number of lymph nodes can try to avoid missing micrometastases is unknown, so it can not be used in clinical practice.In short, there were two reasons of recidivation post operation.:①The primary tumor or micrometastases was not completely cutted, tumor recured in primary tumour site or micro-metastatic sites.②It is a new laryngeal cancer and primary laryngeal cancer has been cured. The new one was the second primary laryngeal carcinoma, whose clonal origins differ from the primartumor. It was always a pending question that the "recurrent" laryngeal carcinoma was a real recidivation after surgical resection or a new tumor who has different clonal origins from the primary tumor. Discriminating them has a very important clinical significance, not only for the study of cancerogenesis but also for determination of therapeutic strategies. For primary tumor either not to consider the function of larynx for extend resection or only resect tumor by naked eye to remain the function as possible. For recurrent tumor how to treat them who had or not had the opportunity for operation. Futher understanding the association of biological features and prognosis of recurrent laryngeal squamous cell carcinoma after surgical resection and primary tumor may provide more theoretical bases for reasonable and standerded treatment of laryngeal squamous cell carcinoma.Since the formation of the various disciplines of occupational bias and other factors, the current comprehensive treatment of laryngeal cancer in clinical practice was not good, especially in when the primary tumour recidivated after operation or second primary cancer emerged. It was a serious impediment to long-term efficacy of surgical patients, decreased quality of life evidently. This study has targeted patients with laryngeal cancer recurred..To examine if these tumors have the same genetic basis or not, we investigated genetic alterations such as allelic loss in primary cancer and so-called "recurrent" tumor to see if they showed identical patterns. Discussion associated treatment and recurrence in the patient, it will provide useful clinical theoretical basis for more rational treatment of laryngeal cancer. The first part Clonal origins of recurrent laryngeal squamous cell carcinoma by Detection of Microsatellite Loss of Heterozygosity[Objective] Recurrent laryngeal squamous cell carcinoma after surgical resection are not such a rare phenomenon in patients. However, It was always a pending question that the "recurrent" laryngeal carcinoma was a real recidivation or a new tumor who has different clonal origins from the primary tumor. The objective of this study was to distinguish genetic basis by analysis of loss of heterozygosity (LOH) in the regions frequently lost in primary tumor and recurrent tumor in the same patient.[MATERIAL AND METHOD] The material from same patients consisted of primary and recurrent tumor. We obtained cancer and adjacent normal tissues by laser capture microdissection. Thirty-eight laryngeal cancer patients were examined for loss of heterozygosity on 3p,5p,7q,8p,9p,13p,17p and 18q chromosomal arms with the use of 10 microsatellite markers. Patterns of the loss of heterozygosity were analyzed in primary tumors and recurrent tumors.RESULTS:Primary tumors and recurrent tumors in the same patient were detected to have identical patterns of allelic loss.CONCLUSIONS:l.The data, obtained during this investigation, did reveal the predictive that primary tumors and recurrent tumors have the same clonal origins in the same patient. In other words, we can say that the "recurrent" laryngeal carcinoma was a real recidivation after surgical resection, it imply that we failed to radically resected primary tumor or the micrometastasis, consequently we need adjunctive therapy, chemotherapy or radiotherapy.2. In our study, loss of heterozygosity of 10 microsatellite markers on multiple chromosomes (3,5,8,9,13) was examined by PCR-SSCP assay in 37 cases with primary tumors and recurrent tumors. According to different LOH patterns, the clonality of multiple tumor was determined in the same patient.3. More than 40% of laryngeal carcinoma showed different patterns of LOH in D3S1234、D5S592、D9S171、D9s104、D3S1300, which suggested that these five markers were more sensitive and specific and could be the first choice of microsatellite markers.4. The history of smoking is longer in LOH group than no-LOH group, so smoking related to the occurrence of LOH.5. The average release time to recurrence after first operation in the group did not detect LOH were longer than the group detected LOH, indicating that laryngeal squamous cell carcinoma recurrence is closely related to chromosomal aberrations.The second partThe study and clinical significance of microsatellite Loss of Heterozygosity in primary laryngeal squamous cell carcinomas which had relapsed[Objective] To study the character and significance of the loss of heterozygosity (LOH) on 3p,5p,9p chromosomal arms in primary laryngeal squamous cell carcinoma which had relapsed.Methods:Allelic deletions analysis was performed with 3 polymorphic markers (D3S1234、D5S592、D9s171) using polymerase chain reaction-single sequence length polymorphism-silver staining in 31 laryngeal squamous cell carcinoma which had relapsed and adjacent tissues. Retrospective analysis of postoperative recurrence of cancer for the first time related to treatment.Result:Allelic loss was seen in 48.3%(15/31),45.2%(14/31),61.3%(19/31) of the three markers. The patients who with LOH detected had a shorter time to recurrence than the patients who with no LOH detected. Statistical significance was found between two teams.Conclusions:1. It was negative correlation between LOH and the time of recurrence, in other words, postoperative recurrence of tumour is associated with chromosome variation.2. The time of tumour recurrence in more allele loci simultaneously detected LOH were shorter than in only single loci detected LOH, namely postoperative recurrence of tumour is associated with the level of chromosome variation. The data, obtained during this investigation did reveal the predictive value of LOH with respect to local relapse occurrence in laryngeal cancer patients.3. The experiment make a retrospective analysis about the relationship between treatment and relapse, found that the patients were deceted LOH in the same level who receive chemotherapy and radiotherapy treatment have a longer release time. It is a effective instruction to choose the best clinical treatment protocols.