Firas al-Ali, diagnosed with a benign tumour near his brain in 2017, has undergone surgery and tests in Turkey, where he usually gets medication and treatment every three months. He had been waiting for treatment on February 23, but then the earthquake struck.
"Due to the delay, I'm getting pain in my eyes and my head," the 35-year-old blacksmith said.
"My treatment is unavailable here and if it is, it is expensive and I can't afford it."
Rebel-held Idlib is home to around three million people, many of them displaced from other parts of Syria and dependent on humanitarian aid.
Government-held areas of Syria are off-limits to civilians from Idlib. The Syrian side of the Bab al-Hawa crossing into Turkey is controlled by the country's former Al-Qaeda affiliate, Hayat Tahrir al-Sham (HTS).
Syrians 'risk dying'
The Syrian American Medical Society (SAMS) runs the only centre in Idlib for cancer patients.
Paediatric oncologist Abdel Razzaq Bakur said the clinic lacked diagnostic equipment and medications and had been overwhelmed by "numerous patients who urgently need to be admitted in Turkey."
The children's ward alone has admitted 30 patients left untreated by the border closure, he said.
Around 40 more "haven't been getting chemotherapy and their condition is very bad -- some risk dying."
Some families had tried to get medicine from Turkey or Lebanon, but prices were often prohibitive, he added.
"Most people can't cover their basic daily needs, so how are they supposed to secure chemotherapy doses?" he asked.
Yusuf Haj Yusuf, 60, was scheduled to have chemotherapy in Turkey the day the quake struck and said a recent scan showed his lung cancer had worsened.
He had asked relatives to help pay for treatment in Idlib but "no longer had the strength" to raise funds.
"I was very happy about the reopening of the crossing," he said.
"After the earthquake, we cancer patients have suffered a lot. We have all been waiting to return to the Turkish hospitals."