Raquel Luque

Testicular germ cell tumors are the most common tumors in adolescent and young men. They are curable malignancies that should be treated with curative intent, minimizing acute and long-term side effects. Inguinal orchiectomy is the main diagnostic procedure, and is also curative for most localized tumors, while patients with unfavorable risk factors for recurrence, or those who are unable or unwilling to undergo close follow-up, may require adjuvant treatment. Patients with persistent markers after orchiectomy or advanced disease at diagnosis should be staged and classified according to the IGCCCG prognostic classification. BEP is the most recommended chemotherapy, but other schedules such as EP or VIP may be used to avoid bleomycin in some patients. Efforts should be made to avoid unnecessary delays and dose reductions wherever possible. Insufficient marker decline after each cycle is associated with poor prognosis. Management of residual masses after chemotherapy differs between patients with seminoma and non-seminoma tumors. Patients at high risk of relapse, those with refractory tumors, or those who relapse after chemotherapy should be managed by multidisciplinary teams in experienced centers. Salvage treatment for these patients includes conventional-dose chemotherapy (TIP) and/or high-dose chemotherapy, although the best regimen and strategy for each subgroup of patients is not yet well established. In late recurrences, early complete surgical resection should be performed when feasible. Given the high cure rate of TGCT, oncologists should work with patients to prevent and identify potential long-term side effects of the treatment. The above recommendations also apply to extragonadal retroperitoneal and mediastinal tumors.

The 2021 World Health Organization (WHO) classification has updated the definition of grade 2 gliomas and the presence of isocitrate dehydrogenase (IDH) mutation has been deemed the cornerstone of diagnosis. Though slow-growing and having a low proliferative index, grade 2 gliomas are incurable by surgery and complementary treatments are vital to improving prognosis. This guideline provides recommendations on the multidisciplinary treatment of grade 2 astrocytomas and oligodendrogliomas based on the best evidence available.

Recent advances in molecular profiling, have reclassified medulloblastoma, an undifferentiated tumor of the posterior fossa, in at least four diseases, each one with differences in prognosis, epidemiology and sensibility to different treatments. The recommended management of a lesion with radiological characteristics suggestive of MB includes maximum safe resection followed by a post-surgical MR < 48 h, LCR cytology and MR of the neuroaxis. Prognostic factors, such as presence of a residual tumor volume > 1.5 cm², presence of micro- or macroscopic dissemination, and age > 3 years as well as pathological (presence of anaplastic or large cell features) and molecular findings (group, 4, 3 or p53 SHH mutated subgroup) determine the risk of relapse and should guide adjuvant management. Although there is evidence that both high-risk patients and to a lesser degree, standard-risk patients benefit from adjuvant craneoespinal radiation followed by consolidation chemotherapy, tolerability is a concern in adult patients, leading invariably to dose reductions. Treatment after relapse is to be considered palliative and inclusion on clinical trials, focusing on the molecular alterations that define each subgroup, should be encouraged. Selected patients can benefit from surgical rescue or targeted radiation or high-dose chemotherapy followed by autologous self-transplant. Even in patients that are cured by chemorradiation presence of significant sequelae is common and patients must undergo lifelong follow-up.

Glioblastoma (GB) is the most common brain malignancy and accounts for over 50% of all high-grade gliomas. Radiotherapy (RT) with concomitant and adjuvant temozolomide (TMZ) chemotherapy is the current standard of care for patients with newly diagnosed GB up to age 70. Recently, a new standard of care has been adopted for elderly patients (≥ 65 years) based on short course of RT and TMZ. Several clinically relevant molecular markers that assist in diagnosis and prognosis have recently been identified. The treatment for recurrent GB is not well defined, and decision-making is usually based on prior strategies as well as several clinical and radiological factors. The presence of neurologic deficits and seizures can significantly impact quality of life.

Carboplatin-paclitaxel is a reference regimen in the treatment of locally advanced or disseminated non-small cell lung cancer (NSCLC). This paper discusses the multidrug resistance developed with this drug combination, which is one of the major obstacles to successful treatment. In order to understand and overcome the drug resistance pattern of NSCLC after carboplatin plus paclitaxel exposure, levels of mRNA expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein 3 (MRP3) were investigated in primary NSCLC cell lines (A-549 and A-427) and a metastasis-derived NSCLC cell line (NODO). Our results showed that exposure of the three NSCLC lines to plasma concentrations of paclitaxel (5 μM) produced an increase in MDR1 expression, while MRP3 showed no alteration in expression. By contrast, the same cells exposed to carboplatin plasma concentrations (30 μM) showed overexpression of MRP3. In these cells, MDR1 showed no expression changes. Interestingly, the combination of both paclitaxel and carboplatin caused increased expression of the MDR1 drug resistance gene rather than the individual treatments. These results suggest that carboplatin and paclitaxel may induce drug resistance mediated by MDR1 and MRP3, which may be enhanced by the simultaneous use of both drugs.

97 Background: Multidrug resistance (MDR) phenotype is the major cause of chemotherapy failure. It has been related to several proteins expression: P-glycoprotein (PgP), MRP family, LRP, and BCRP. We study the resistance pattern induced after paclitaxel and carboplatin in non-small cell lung cancer (NSCLC). Methods: We used 5 different cell lines. A549 and A427 cell lines were derived from lung epithelial carcinoma. NODO line was obtained from lung carcinoma metastases, and 3 cell lines derived from other tumours: gastric cancer (GAS), seminoma (SEM), breast cancer (MCF7). The cell lines were exposed to paclitaxel, carboplatin, and the combination of both drugs. The concentrations we used were similar to the plasma concentrations observed in patients treated previously. Results: A549 cell line did not show basal expression of MDR1, but a weak basal expression of MRP3 was observed. After chemotherapy, we observed that paclitaxel induced MDR1 and carboplatin induced MRP3. The combination of both drugs induced MDR1 and MRP3 expression, however, when paclitaxel is associated to carboplatin, MRP3 expression did not increase significantly. A427 cell line did not show basal expression of MDR1 and MRP3. Paclitaxel induced MDR1 and carboplatin induced MRP3. The association of both drugs increased significantly the expression of MDR1, and very few the expression of MRP3. NODO cell line did not show any basal expression. Paclitaxel induced MDR1 and carboplatin induced MRP3. Cell lines derived from other tumours not show any basal expression. Paclitaxel induced MDR1 in all cell lines. Carboplatin did not induce MDR1, nor MRP3 in GAS cell line. Conclusions: Plasma concentrations of paclitaxel induced MDR1 expression but not MRP3 in lung cancer and other tumours derived cell lines. Carboplatin produced overexpression of MRP3 but not MDR1 in the same cell lines. The combination of both drugs at plasma concentrations was not able to activate a new resistance mechanism in the studied cell lines, but improve the resistance mechanism induced by each one of the drugs individually.

96 Background: Non-small cell lung cancer (NSCLC) is sometimes chemoresistant and does not respond to treatment; several factors are involved in the development of chemoresistance, such as multidrug resistance (MDR) phenotype, mainly. Methods: We studied MDR1 gene expression in peripheral blood PMN of 23 patients with NSCLC, advanced stages in most of the cases, who had not received treatment previously, before (hour 0) and after (hour 6) paclitaxel-carboplatin treatment. RNA was obtained from PMN pellet by means of the protocol of trizol. RNA was checked with agarose gels, and later RT-PCR technique was carried out using specific primers. Expression levels were randomly distributed, so that overexpression under 3 was considered low level of expression, and overexpression above 4 was considered high level of expression. Results: After treatment, we found overexpression of MDR1 in 22 patients. High levels were found in 11 patients, and low levels were observed in the other 11 patients. No relation was found between this fact and the treatment response or survival rate. No significant differences in expression were found in the other variables: gender, tobacco habit, weight loss at the diagnosis, tumour staging, and tumor histology. Conclusions: We can conclude that MDR1 expression in peripheral blood is not a predictive factor for treatment response nor a prognostic factor of the disease. Despite these results, further studies are necessary on molecular biology of NSCLC in order to try to establish subgroups of patients based on genetic profiles, in which the use of microarrays could be very useful.