The impact of COVID-19 on cancer care and oncology clinical research: an experts' perspective.

The coronavirus disease-19 (COVID-19) pandemic promises to have lasting impacts on cancer clinical trials that could lead to faster patient access to new treatments. In this article, an international panel of oncology experts discusses the lasting impacts of the pandemic on oncology clinical trials and proposes solutions for clinical trial stakeholders, with the support of recent data on worldwide clinical trials collected by IQVIA. These lasting impacts and proposed solutions encompass three topic areas. Firstly, acceleration and implementation of new operational approaches to oncology trials with patient-centric, fully decentralized virtual approaches that include remote assessments via telemedicine and remote devices. Geographical differences in the uptake of remote technology, including telemedicine, are discussed in the article, focusing on the impact of the local adoption of new operational approaches. Secondly, innovative clinical trials. The pandemic has highlighted the need for new trial designs that accelerate research and limit risks and burden for patients while driving optimization of clinical trial objectives and endpoints, while testing is being minimized. Areas of considerations for clinical trial stakeholders are discussed in detail. In addition, the COVID-19 pandemic has exposed the underrepresentation of minority groups in clinical trials; the approach for oncology clinical trials to improve generalizability of efficacy and outcomes data is discussed. Thirdly, a new problem-focused collaborative framework between oncology trial stakeholders, including decision makers, to leverage and further accelerate the innovative approaches in clinical research developed during the COVID-19 pandemic. This could shorten timelines for patient access to new treatments by addressing the cultural and technological barriers to adopting new operational approaches and innovative clinical trials. The role of the different stakeholders is described, with the aim of making COVID-19 a catalyst for positive change in oncology clinical research and eventually in cancer care.

Sequence effect of irinotecan and fluorouracil treatment on pharmacokinetics and toxicity in chemotherapy-naive metastatic colorectal cancer patients.

PURPOSE: To investigate the sequence effect of irinotecan and a 48-hour infusion of fluorouracil (5-FU) modulated by leucovorin (LV) on the plasma pharmacokinetics of irinotecan and its metabolites, the toxicity profile of this combination, and irinotecan's maximum-tolerated dose (MTD). PATIENTS AND METHODS: Thirty-three metastatic colorectal cancer patients were randomized to receive a 60-minute infusion of irinotecan before or after a 48-hour infusion of 5-FU modulated by LV. The reverse sequence was used after 21 days for the second cycle. 5-FU 3,500 mg/m2 was preceded by l-LV 250 mg/m2. Irinotecan 150 mg/m2 (starting dose) was administered to the first three patients. The dose was escalated by 50 mg/m2 in subsequent groups of three to six patients to determine the MTD for both sequences. Pharmacokinetic analysis of irinotecan and its metabolites was performed after each cycle. RESULTS: Toxicities were affected by the sequence of administration of irinotecan and 5-FU, with an improved tolerability for irinotecan followed by 5-FU. The irinotecan MTD was reached at 300 mg/m2 when irinotecan followed 5-FU and at 450 mg/m2 when it preceded 5-FU. In seven of 23 patients who received both sequences at identical irinotecan doses, the dose-limiting toxicity was observed only when irinotecan followed 5-FU. Pharmacokinetic analysis revealed that the administration sequence significantly affected the SN-38 area under the concentration-versus-time curve (AUC), which was 40.1% lower (P <.05) when irinotecan preceded 5-FU. CONCLUSION: The sequence of treatment with irinotecan and infusional 5-FU affects the tolerability of this combination. This can be explained in part by a reduced SN-38 AUC when irinotecan preceded infusional 5-FU. Well-defined 5-FU/irinotecan regimens are needed because the administration sequence or the interval between the agents might affect treatment tolerance and perhaps also activity.

Accelerated-intensified cyclophosphamide, epirubicin, and fluorouracil (CEF) compared with standard CEF in metastatic breast cancer patients: results of a multicenter, randomized phase III study of the Italian Gruppo Oncologico Nord-Ouest-Mammella Inter Gruppo Group.

PURPOSE: To evaluate whether an accelerated-intensified cyclophosphamide, epirubicin, and fluorouracil (CEF) chemotherapy regimen with the support of granulocyte colony-stimulating factor (G-CSF) induces a higher activity and efficacy compared with standard CEF in metastatic breast cancer patients. PATIENTS AND METHODS: Stage IV breast cancer patients were randomized to receive as first-line chemotherapy either standard CEF (cyclophosphamide 600 mg/m(2), epirubicin 60 mg/m(2), and fluorouracil 600 mg/m(2)) administered every 21 days (CEF21) or accelerated-intensified CEF (cyclophosphamide 1,000 mg/m(2), epirubicin 80 mg/m(2), and fluorouracil 600 mg/m(2)) administered every 14 days (HD-CEF14) with the support of G-CSF. Treatment was administered for eight cycles. RESULTS: A total of 151 patients were randomized (74 patients on the CEF21 arm and 77 on the HD-CEF14 arm). In both arms, the median number of administered cycles was eight. The dose-intensity actually administered was 93% and 86% of that planned, in CEF21- and HD-CEF14-treated patients, respectively. Compared with the CEF21 arm, the dose-intensity increase in the HD-CEF14 arm was 80%. Both nonhematologic and hematologic toxicities were higher in the HD-CEF14 arm than in the CEF21 arm. During chemotherapy, four deaths occurred in the HD-CEF14 arm. No difference in overall response rate (complete plus partial responses) was observed: 49% and 51% in the CEF21 and HD-CEF14 arms, respectively (P =.94). A slightly non-statistically significant higher percentage of complete response was observed in the HD-CEF14 arm (20% v 15%). No difference in efficacy was observed. The median time to progression was 14.3 and 12.8 months in the CEF21 and HD-CEF14 arms, respectively (P =.69). Median overall survival was 32.7 and 27.2 months in the CEF21 and HD-CEF14 arms, respectively (P =.16). CONCLUSION: In metastatic breast cancer patients, an 80% increase in dose-intensity of the CEF regimen, obtained by both acceleration and dose intensification, does not improve the activity and the efficacy compared with a standard dose-intensity CEF regimen.

Hashimoto's thyroiditis in association with Tolosa Hunt syndrome: a case report.

Tolosa Hunt syndrome (THS) is a painful ophthalmoplegia due to a nonspecific inflammatory process in the cavernous sinus or to parasellar neoplasms. Although the cause of the disease is unknown, previous observations support the hypothesis that THS may be only one manifestation of a generalized vasculitis. The diagnosis is based on findings of painful ophthalmoplegia, excellent response to corticosteroids, and exclusion of other causes including aneurysm, diabetes mellitus, paranasal mucocele, and carotid cavernous fistula. We report the case of a 24-year-old woman with THS who had undergone thyroidectomy 4 years before admission for goiter with histologic diagnosis of Hashimoto's thyroiditis. This case shows the unusual association between Hashimoto's thyroiditis and THS and supports the autoimmune origin of both diseases.

Ototoxicity resulting from intracochlear perfusion of Streptococcus pneumoniae in the guinea pig is modified by cefotaxime or amoxycillin pretreatment.

Acute changes in the electrophysiology and ultrastructure of the organ of Corti were studied after microperfusion of c. 5 x 10(6) CFU of serotype 2 Streptococcus pneumoniae D39 or Escherichia coli K-12 directly into the scala tympani of guinea pigs. Hearing loss was assessed by recording the auditory nerve compound action potential response to a 10 kHz tone pip. Mean hearing loss 3 h after pneumococcal perfusion (n = 4) was 44 dB, compared to 6 dB after E. coli perfusion (n = 4) (P<0.001). After pneumococcal perfusion, scanning electron microscopy revealed damage to hair cell stereocilia and cratering of the apical surface of supporting cells. Intraperitoneal injection of 100 mg/kg cefotaxime (n = 4) or 100 mg/kg amoxycillin (n = 4) 30 min before perfusion of pneumococci significantly reduced mean hearing loss to 23 dB (P=0.01) or 20 dB (P=0.01), respectively, and diminished ultrastructural damage. The data suggest that if pneumococci invade the inner ear during meningitis, cochlear deafness may rapidly ensue.

Kanamycin ototoxicity and pigmentation in the guinea pig.

Cochleas from albino and pigmented guinea pigs were examined histologically following chronic administration of Kanamycin. In pigmented animals, damage was concentrated amongst hair cells towards the base, but in albinos, hair cell damage was diffusely spread. These observations support suggestions that melanin is implicated in Kanamycin ototoxicity.

Threshold sensitivity of the auditory pathway: effects of worsening signal-to-noise ratio in the auditory nerve.

Perfusions of scala tympani with high potassium solutions increase spontaneous activity of auditory nerve fibres without affecting their threshold sensitivity. In these circumstances, however, the signal-to-noise ratio of the auditory nerve response to a given stimuli is worsened. Recordings from cochlear nucleus neurones during such perfusions indicate that this worsening is critical for threshold sensitivity at higher levels in the auditory pathway.

Vulnerability of tip links between stereocilia to acoustic trauma in the guinea pig.

The cochleae of anaesthetized guinea pigs were prepared for scanning electron microscopy, immediately after exposure to an intense tone. Stereocilia on hair cells showing relatively small degrees of disruption were analyzed. If the bundles of stereocilia showed no or only a very slight degree of disorganization, the fine links emerging from the tips of the shorter stereocilia remained intact. If the stereocilia were separated more than a very little, the tip links between stereocilia were no longer visible. However, it was possible for tip links to remain intact in some parts of the hair bundle, while tip links in other, more disrupted parts, were lost. In outer hair cells, tip links did not seem any more vulnerable in one position than in another. In inner hair cells, it was commonly found that the tip links running between the tallest stereocilia and the next row of shorter stereocilia had broken, while the tip links running between the other shorter rows of stereocilia remained intact. The results suggest that tip links between stereocilia are preserved as long as the other links between the stereocilia and the cytoskeleton of the stereocilium remain intact. When the latter are damaged the tip links fracture. The results also suggest that, if the tip links are indeed involved in transduction, some degree of stimulus transduction can continue in damaged inner hair cells, albeit with a reduced sensitivity.

The effect of chronic application of kanamycin on stereocilia and their tip links in hair cells of the guinea pig cochlea.

Albino guinea pigs were treated with kanamycin (400 mg/kg i.p.) daily for 10 days. After a 2-week recovery period their cochleae were analyzed by scanning electron microscopy. Attention was paid to those outer hair cells which had been less severely damaged. Stereocilia of the outer hair cells were often constricted at the root, and in some cases had become detached at the root. In stereocilia showing any degree of abnormality, the tip links were usually missing. However, in a few exceptional cases, tip links could remain on stereocilia showing other abnormalities, such as constriction at the root. Where hair cells were otherwise apparently unaffected, a much higher proportion of tip links remained, even on cells situated in an area of extensive hair cell loss. The results give further information on the process of kanamycin poisoning. They also suggest that substantial loss of tip links, and therefore perhaps of transduction, is one of the preliminary consequences of kanamycin poisoning.

Further observations on the fine structure of tip links between stereocilia of the guinea pig cochlea.

Stereocilia of the guinea pig organ of Corti were examined by transmission electron microscopy, after fixation in glutaraldehyde and tannic acid, and postfixation and en bloc staining in osmium tetroxide, tannic acid, uranyl acetate, and phosphotungstic acid. Tip links were observed between the stereocilia. The links emerged from the tips of the shorter stereocilia in the hair bundle, running nearly at right angles to the cuticular plate, to join the side-wall of the adjacent taller stereocilium of the next row. The tip links had a fine filamentous core, approximately 6 nm in diameter. The core was surrounded by positively-staining amorphous material, which had a variable appearance from link to link. The central filament inserted into membrane specialisations at both its upper and lower ends. The results suggest that tip links have two components, and that the central filament, which has the same diameter as an actin filament, is suitable for transmitting stimulus-induced movements to the transducer channels of the stereocilium. The central filament would therefore concentrate the stimulus-induced forces onto a small area of cell membrane.

Cross-links between stereocilia in the guinea pig organ of Corti, and their possible relation to sensory transduction.

Hair cells of the guinea pig cochlea were preserved for electron microscopic examination by fixing in glutaraldehyde without the use of osmium. An extensive array of cross-links was seen between the stereocilia, by both scanning and transmission electron microscopy. The stereocilia were linked together laterally, particularly near their apical ends, by links running approximately at right angles to the long axis of the stereocilia. One set joined stereocilia of the same row, and another set joined stereocilia of the different rows, holding the tips of the shorter stereocilia in towards the longer stereocilia of the next row. In addition, the tip of each shorter stereocilium on the hair cell gave rise to a single, upwards-pointing link, which ran up to join the taller stereocilium of the next row. We suggest that distortion of this link would give rise to sensory transduction. On this basis, we are able to explain the V shape of the rows of stereocilia on outer hair cells. Within the rows, the three-dimensional arrangement of the stereocilia was different from that seen conventionally. Rather than standing parallel, the stereocilia of the different rows tapered in together at the tips, presumably held by the laterally-running cross-links. In addition, a membrane roughness, particularly pronounced in the region of the stereocilium which gives rise to the cross-links, was seen. However, the lateral and basal surface membranes of the hair cell, and the membranes of the internal organelles, had a more conventional appearance.

Tip-link organization in anomalously-oriented hair cells of the guinea pig cochlea.

Stereocilia are described in a group of guinea pigs with abnormal conformation of the outer hair cell stereociliary bundles. Rows of stereocilia were found which were circular instead of V- or W-shaped, and rotated or even reversed in orientation with respect to normal. The stereocilia have however a normal gradation in heights of the rows of stereocilia, and have tip links running in the direction of gradation in height.

The organization of tip links and stereocilia on hair cells of bird and lizard basilar papillae.

Auditory papillae from three species of bird (pigeon, starling, and chick), and two species of European lizard (Podarcis muralis and Podarcis sicula) were examined by scanning electron microscopy. Hair bundles from all papillae showed tip links oriented along the direction of gradation in heights of the stereocilia (i.e. parallel to the hair-cell axis of bilateral symmetry, and so parallel to the excitatory-inhibitory axis for mechanotransduction). This orientation was seen irrespective of the overall orientation of the hair bundle within the papilla. The stereocilia formed columns, joined by the tip links, which ran parallel to the hair-cell axis of bilateral symmetry. The stereocilia within the same column tended to stay together, while those in different columns tended to separate during preparation. In many columns all the stereocilia tended to be a little taller, or a little shorter, than the equivalent stereocilia in adjacent columns, suggesting that all the stereocilia within one column had been affected by a common height determinant during development. In addition, links running laterally between stereocilia were seen, in a band near the base of the stereocilia. The results are consistent with the hypothesis that tip links are a universal feature of mechano-transducing acousticolateral hair cells, and that they are involved in sensory transduction. The results also support suggestions that the tip links may play a role in determining the heights of the stereocilia during development.

The effect of potassium on the activity of auditory nerve fibres of the guinea pig cochlea.

Scala tympani of the guinea pig cochlea was perfused with solutions having an increased potassium concentration. The response characteristics of single auditory nerve fibres in both normal and kanamycin-damaged cochleas were studied using computer controlled routines. The results indicate that these perfusions caused a marked increase in the spontaneous firing rate of auditory nerve fibres, without loss of threshold sensitivity. Current theories of cochlear transduction support the view that the potassium concentration difference across the reticular plate is fundamental to the sensitivity of the cochlea. The results presented here do not support this view.

Action of elastase, collagenase and other enzymes upon linkages between stereocilia in the guinea-pig cochlea.

Enzymes, which degrade elements of the extracellular environment, were studied for their actions upon stereocilia and their cross-linkages by scanning electron microscopy. Chondroitinase, hyaluronidase and keratanase, which attack carbohydrate moieties of the extracellular matrix, had little effect upon hair bundles. Collagenase and plasmin (fibrinolysin) also had only marginal effects. Elastase produced dramatic effects upon hair bundles. Both lateral and tip links were degraded resulting in separation and splaying of stereocilia. Many stereocilia showed no marked loss of rigidity, although some were bent or kinked. In general, inner hair cells were the most susceptible to elastase followed by row 3, row 2, row 1 of the outer hair cells. The proteolytic enzyme trypsin did not noticeably disrupt the hair bundles. Protease caused loss of rigidity and fracture of stereocilia resulting in considerable collapse of hair bundles. Crosslinkages between stereocilia were less noticeably degraded. These results indicate that both lateral and tip links of stereocilia comprise a proteinaceous moiety which could be elastin or some chemically related structure.

NG-methyl-L-arginine protects the guinea pig cochlea from the cytotoxic effects of pneumolysin.

Sensorineural hearing loss is a major sequela of the bacterial meningitis associated in particular with Streptococcus pneumoniae. Recent studies have shown pneumolysin, a toxin elaborated by S. pneumoniae, to be cytotoxic to the guinea pig cochlea. The mechanisms of this cytotoxicity are, however, not fully understood. In the present study this deleterious action of pneumolysin has been shown to be blocked by pretreating the cochlea with NG-methyl-L-arginine, a known inhibitor of nitric oxide synthesis. Furthermore, pretreatment of the cochlea with MK-801, an NMDA receptor antagonist, was also found to confer marked protection from the action of pneumolysin. This latter finding is consistent with previous reports that excess stimulation of NMDA receptors within the cochlea, an event known to lead to excess nitric oxide release, have similar effects on the cochlea as pneumolysin perfusion. It would therefore appear that nitric oxide may represent a significant link in the chain of events leading to the deafness of bacterial meningitis.

Hair cell loss in the aged guinea pig cochlea.

The various effects of ageing on the auditory system, collectively termed presbycusis, are being studied across a wide range of animal species, including humans. One contributing factor to presbycusis is thought to be losses of the sensory hair cells in the cochlea. In this study, hair cell counts were obtained from cochleas of pigmented guinea pigs (Cavia porcellus) at ages ranging from 11 days to 4 years 7 months, using scanning electron microscopy to visualize the organ of Corti. Representative samples of the basal, middle and apical turn of the cochlea were photographed for analysis. Hair cell loss was observed, even in young animals. However, the loss was greater in the aged animals, but was not distributed evenly throughout the length of the cochlea. No significant loss of hair cells was seen in the basal (high frequency) or middle turn of the cochlea of the aged animals. In the apical (low frequency) turn, there was a significant loss of hair cells in all rows of outer hair cells (up to around 20%), and was most severe in the third row. There was no loss of apical inner hair cells in the aged animals.

Effect of furosemide upon morphology of hair bundles in guinea pig cochlear hair cells.

Furosemide was administered by intraperitoneal injection and intracochlear perfusion. The peak-to-peak amplitude of the cochlear microphonic at high sound intensities was reduced however the drug was administered. After a period of time ranging from 1-4 h following drug application, cochleae were fixed and prepared for scanning electron microscopy to examine the hair cells. Changes in the hair bundles from basal turns tended to be more extensive than those of more apical turns. Initially there was an increase in the granularity of the surface of the stereociliary membrane and a tendency for cross-links to swell, stretch and break. Later, the surface texture of stereocilia became smoother than normal, and hair cells in the basal turns showed extensive erosion and fracture of cross-links. Tip links could survive even when extensively stretched. It is possible that the morphological changes in stereocilia reported here do not arise from direct actions of furosemide, but indirectly, from perturbations of the ionic composition of cochlear fluids induced by effects of the drug upon the stria vascularis.

Possible involvement of nitric oxide in the sensorineural hearing loss of bacterial meningitis.

Microperfusion of scala tympani with the NO donors, sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP), produced marked depression of the compound action potential (CAP) and cochlear microphonic (CM) together with severe and widespread morphological damage to hair cells and supporting cells in the organ of Corti. In addition, direct perfusion of N-methyl-D-aspartate (NMDA) into scala tympani, which probably induces excess stimulation of NMDA receptors within the cochlea and which is known to lead to the release of NO, was found to elicit similar electrophysiological and structural lesions in the cochlea. Pre-perfusion of scala tympani with L-methyl arginine (L-MA), which inhibits the release of NO, or superoxide dismutase (SOD), an O2-scavenger, conferred marked protection upon the cochlea from the lesions caused by NO donors. These observations indicate that enhanced NO production is likely to be an important factor responsible for pathological insult of the cochlea. The possibility is discussed that this factor is involved in the chain of events leading to hearing loss caused by bacterial meningitis. Such hearing loss is a major sequela of bacterial meningitis in children.

Ultrastructural damage to the organ of corti during acute experimental Escherichia coli and pneumococcal meningitis in guinea pigs.

Experimental meningitis was induced in 16 pigmented guinea pigs by subarachnoid inoculation of mid log-phase 1 x 10(9) E. coli K-12 (n = 8) or 5 x 10(7) Streptococcus pneumoniae type 2 (n = 8). Animals were killed at various times between 3 and 12 h after inoculation and the ultrastructure of the organ of Corti (including the basilar membrane) was examined with high resolution scanning electron microscopy. Both E. coli and S. pneumoniae induced meningitis and invaded scala tympani. In both types of meningitis the apical surface of inner supporting cells developed craters. inner hair cell stereocilia were also disrupted. In pneumococcal meningitis both these lesions were more pronounced but in addition there were breaks in the junctions between inner hair cells and their adjacent supporting cells and there was ballooning and rupture of the apical surface of outer hair cells. Damage to the organ of Corti after bacterial invasion of the inner ear may be one of the mechanisms by which bacterial meningitis can cause deafness. The more severe cochlear lesions induced by S.pneumoniae may explain the higher incidence of deafness after pneumococcal meningitis.