Targeted Therapy, Chemotherapy, Immunotherapy and Novel Treatment Options for Different Subtypes of Salivary Gland Cancer

Abstract

Surgical resection remains the first line treatment for salivary gland cancer (SGC). In the case of locally advanced disease, surgery is followed by adjuvant radiotherapy. Surgical resection should be favored in resectable locoregional recurrent disease as well, and even the complete resection of all distant oligometastases has clinical benefit for the patients. For inoperable and disseminated metastatic disease, a multitude of systemic therapies including chemotherapy, targeted therapy, and immunotherapy are available. In this review, the current therapeutic options for inoperable recurrent or metastatic SGCs are summarized. Systemic treatment can achieve prolonged progression-free and overall survival, while the overall prognosis remains poor. Current clinical trials include only a limited number of patients and mostly combine different histologic subtypes. Additionally, no randomized controlled trial comparing different therapeutic options has been performed. In the future, further studies with a larger patient cohort and ideally only one histologic subtype are needed in order to improve the outcome for SGC patients. However, this may be difficult to accomplish due to the rarity and diversity of the disease. Additionally, molecular analyses need to be performed routinely in order to individualize treatment and to go one step further towards precision medicine.

Survival in Patients with Primary Parotid Gland Carcinoma after Surgery—Results of a Single-Centre Study

“…However, no randomized controlled trials compare survival outcomes between different targeted systemic therapies in patients with salivary gland carcinomas. Chemotherapy can be always used, while few clinical trials have been conducted regarding the efficacy of immunotherapy targeting PD-1/PD-L1 and CTLA-4 [ 36 ].…”

Establishment of Mucoepidermoid Carcinoma Cell Lines from Surgical and Recurrence Biopsy Specimens

“…This finding indicates that the three cell lines have the same origin. Although the prognosis for MEC patients with a CRTC1-MAML2 chimeric gene is favorable, there is currently no alternative treatment for situations where the disease has worsened or recurred [ 21 ]. Therefore, establishing MEC cell lines derived from the initial surgery and recurrent biopsy specimens upon recurrent is critical for understanding disease progression and developing novel therapeutics.…”

“…Immunotherapy using immune checkpoint inhibitors (ICIs) has been extensively used for various tumors. However, few clinical trials and basic research have focused on MEC immunotherapy, and its effects are unknown [ 21 ]. Recently, an advanced high-grade MEC patient was completely cured by first-line pembrolizumab treatment [ 32 ].…”

“…Chemotherapy and radiation therapy can be combined, although the overall survival is not improved compared to radiation alone [ 17 , 18 , 19 , 20 ]. Although novel therapeutics for MEC targeting CRTC1/3-MAML2 are being explored, there is currently no viable alternative to surgery [ 21 ]. Especially, novel therapeutics for postoperative recurrent cases are needed.…”

The Therapeutic Landscape of Salivary Gland Malignancies—Where Are We Now?

“…Novel treatment options, combined with Notch inhibitors, are therefore needed in this clinically poor group. In addition, multiple research groups are focusing on molecular abnormalities (DNA as well as RNA) which may be of use for SGMs [ 154 , 155 , 156 , 157 , 158 , 159 , 160 ]. Selecting patients based on the tumor molecular profile can be considered a major advantage and should be recommended as this can guide the development of novel therapeutic strategies according to disease biology and further personalize patient treatment.…”