Rare & Complex Cancers

Being diagnosed with a rare or complex cancer often means facing uncertainty, limited research, and fewer standard treatment options. At the Cancer Center of Southern California, we specialize in guiding patients through these difficult circumstances.
Our team frequently treats rare cancers, such as thymic cancer and mesothelioma, as well as complex cases of unknown primary tumors and other unclassified cancers. Many of our patients come to us after exhausting local treatments in search of answers and new possibilities.
Call us at (310) 552-9999 or complete our online form to schedule a consultation today.
Rare & Complex Cancers We Treat
Our center focuses on cancers that are uncommon, difficult to classify, or lack a clear standard of care. These cases require deep expertise, careful investigation, and often involve innovative treatment approaches.
Thymic Cancer
Thymic tumors are rare cancers that develop in the thymus gland, located in the chest. Due to their rarity, finding a specialist with extensive experience in treating them can be challenging.
Mesothelioma
Mesothelioma is an aggressive and rare cancer that forms in the lining of the lungs, abdomen, or heart. It is most often linked to asbestos exposure. This cancer demands a high level of expertise due to its resistance to conventional treatments.
Unknown Primary Tumors (Cancers Without a Home)
One of the most challenging diagnoses a patient can face is an unknown primary tumor, where a clear diagnosis of the cancer's origin is not possible. Also known as cancer of unknown primary (CUP) or an occult primary cancer, this can leave patients feeling lost and without a clear treatment plan.
Unclassified/Complex Cases
We frequently treat patients whose cancer falls outside of a typical classification or those who have faced numerous recurrences. These complex cases require a fresh perspective and a willingness to explore therapies that are not yet standard practice.
Challenges in Treatment of Rare & Complex Cancer
Rare and complex cancers lack standardized treatment protocols. Unlike more common cancers with established guidelines, a rare diagnosis often means there is no clear playbook for care.
- Limited treatment options or effective first-line therapy
- Treatments that work only partially or stop working too soon
- Limited research and fewer clinical trials available
- Diagnostic delays or difficulty in identifying the tumor
- Lack of specialists and oncologists with deep expertise in the treatment
These barriers can leave patients overwhelmed and without a clear path forward.
Second Opinions for Complex Cases
At the Cancer Center of Southern California, we believe there is almost always another path to explore. Our approach is specifically designed for patients who have exhausted standard options and are seeking a different path forward.
Here is how we help patients with rare and complex cancers.
Our specialists re-examine pathology and genetic testing to confirm diagnoses and prognosis.
We assess previously used therapies and explore new avenues for treatment, including investigational drugs and new dosing methods.
Our center provides access to a wide range of trials, giving our patients early access to promising new drugs and treatment methods.
We aim to see patients quickly and start the evaluation process without unnecessary delays. When possible, we try to meet with you within the same week.
Leaders in Research & Complex Cancers
At the core of the Cancer Center of Southern California is a legacy of pioneering research and a commitment to advancing oncology. Our approach is not simply to follow existing standards, but to help define the next generation of cancer treatment, particularly for rare and complex cases.
Leading this effort is Dr. Sant P. Chawla, a widely published oncology expert with a distinguished background. He trained at MD Anderson Cancer Center and went on to co-lead the cancer program at Cedars-Sinai before establishing our center in Santa Monica.
With over 30 years of experience, Dr. Chawla has served as principal investigator for numerous clinical trials that have led to the approval of breakthrough cancer therapies, many of which have since become the standard of care worldwide.
Under Dr. Chawla’s leadership, our center has built a reputation as one of the nation’s most experienced programs for rare and complex cancers. Our team of oncologists continues this tradition by leading clinical studies, collaborating with top institutions, and expanding access to the most advanced treatments available.
How We Treat Rare & Complex Cancers
At the Cancer Center of Southern California, we are dedicated to pioneering new pathways. Every rare and complex cancer case is unique and deserves a custom approach. We develop a custom protocol tailored to the specific biology of your tumor.
These pathways may include the following.
- Off-label drugs may be used when an approved therapy shows promise outside its standard indication
- Expanded access programs or single-patient INDs can allow the use of investigational drugs not yet widely available
- Enrollment in clinical trials is possible for rare and complex cancers
- Alternative dosing strategies may be designed to increase effectiveness while reducing toxicity
- Our whole-body approach is focused not only on outcomes but also on maintaining quality of life throughout treatment
Our oncologists collaborate with leading specialists from top institutions, such as Cedars-Sinai, UCLA, and USC. This network allows us to develop truly personalized treatment pathways for patients with difficult-to-diagnose and hard-to-treat cancers. We combine their expertise with our own decades of research to find answers.
Clinical Trials for Rare Cancers
For many patients with rare or complex cancers, clinical trials are not a last resort, but often the most promising path forward. We make these cutting-edge therapies accessible to patients.
Our staff helps manage paperwork, authorizations, and trial coordination.
In many cases, trial sponsors cover the cost of investigational drugs, and sometimes even travel or lodging for the patient.
From eligibility screening to ongoing monitoring, we guide patients and families through the entire process.
Patients with HMO or Kaiser coverage can often still join trials through our center.
For patients who may not qualify for a trial but still need investigational therapies.
Get Treatment for Rare & Complex Cancers
If you’ve been told that no options remain, you are not alone. At the Cancer Center of Southern California, we specialize in giving patients with rare and complex cancers a new path forward. We are ready to review your case and explore every possible option with you.
To schedule an appointment, please call us at 310-552-9999 or request an appointment online.
Frequently Asked Questions
A rare cancer is one that affects a small number of people each year. A complex cancer is one that is difficult to diagnose or treat, often without a clear standard of care. This includes unknown primary tumors, Mesothelioma, and other unclassified cases.
We specialize in providing a comprehensive second opinion for patients who have exhausted standard treatments. Our team is dedicated to exploring innovative options, including personalized protocols, clinical trials, and expanded access to therapies.
Yes. The list of cancers on our website is not exhaustive. Our team is equipped to handle a wide range of rare and unclassified malignancies. We encourage you to contact us for a consultation to review your specific case.
The Cancer Center of Southern California is a leading center for clinical trials for rare and complex cancers. We can help you navigate the eligibility and enrollment process for both investigator-initiated and pharmaceutical-initiated trials.
We understand that time is critical. Our team works to schedule new patient consultations as quickly as possible, often within a few days or weeks, to ensure you can get the answers you need and begin a new treatment path without delay.
Yes. Our team works directly with you and your insurance provider to help navigate the process and understand your coverage. We also assist with programs to help patients obtain free treatments from pharmaceutical companies through sponsorship programs.


