Clinical Analysis of En Bloc Resection for Advanced Temporal Bone Squamous Cell Carcinoma

Abstract

Objective En bloc and margin-negative surgical resection seems to offer the best prognosis for patients with temporal bone squamous cell carcinoma (TB-SCC). In this study, we summarize the outcomes of surgical cases of advanced TB-SCC (T3–T4) that were managed in two institutions, with an accompanying description of the surgical procedure that was utilized: modified subtotal temporal bone resection (STBR), which involves the en bloc removal of the temporal bone including or transecting the otic capsule. Design This is a case series study with chart review. Setting The study was conducted at two academic tertiary care medical centers. Participants Chart information was collected for all patients who underwent surgical resection of advanced TB-SCC between July 1998 and February 2019. The resulting dataset contained 43 patients with advanced TB-SCC who underwent en bloc resection during the review period. Tumor staging followed the modified Pittsburgh classification. Disease-specific survival (DSS) rates were calculated according to the Kaplan–Meier method. Main Outcome Measure This study shows disease-specific 5-year DSS rate. Results The 5-year DSS rate of the cases who underwent en bloc resection was 79.7%. En bloc lateral temporal bone resection was employed in a total of 25 cases (DSS: 79.0%). En bloc modified STBR was utilized in 18 cases (DSS: 81.7%). Conclusion En bloc margin-negative resection is a reliable treatment strategy for advanced TB-SCC. Modified STBR can be a treatment option for TB-SCC without marked posterior extension.

Variations of en Bloc Resection for Advanced External Auditory Canal Squamous Cell Carcinoma: Detailed Anatomical Considerations

“…Conventionally, malignant tumors of the head and neck are treated with en bloc tumor resection to the set safety margins. Zanoletti et al reported that recurrences occurred despite obtaining block resection with negative margin in EAC-SCC [ 15 ], but many previous studies concluded that negative margin resection can improve the prognosis of EAC-SCC [ 16 , 17 , 18 , 19 , 20 , 21 ]. It may be difficult to control positive margin resection with adjuvant therapy [ 22 , 23 , 24 , 25 ], although some studies recommended a piecemeal approach for cases requiring treatment beyond LTBR due to the technical difficulty [ 2 , 3 , 4 , 26 ].…”

“…This method does not require a retromastoid paracondylar approach and, instead, involves a limited posterior mastoidectomy. The limited posterior mastoidectomy enabled us to cut the internal auditory meatus and expose the jugular foramen from the lateral aspect [ 16 ]. However, there is a debate with the mSTBR approach.…”

“…In case of invasion of the mastoid cavity by the tumor, which would result in mastoid opacification, the opening of the cavity can prevent the surgeon from achieving a negative resection margin. Nakagawa’s group achieved negative margin resection in 10 of 13 patients who underwent mSTBR [ 16 ]. They administered preoperative chemoradiotherapy, which possibly limited the ability of micrometastatic cells to proliferate in the cavity [ 16 ].…”

“…Nakagawa’s group achieved negative margin resection in 10 of 13 patients who underwent mSTBR [ 16 ]. They administered preoperative chemoradiotherapy, which possibly limited the ability of micrometastatic cells to proliferate in the cavity [ 16 ]. Currently, there is no evidence that opening a fluid-filled mastoid cavity worsens patient outcomes.…”

“…However, we revealed that only T4 status, not T3 status, was associated with poor prognosis [ 18 ]. Even for T4 cases, the en bloc resection with a negative surgical margin can improve the prognosis [ 16 , 17 ]. In the modified Pittsburgh classification system, T4 cases include the two types of cases that can be treated with either LTBR or STBR for curative resection.…”